diff --git a/.gitignore b/.gitignore
index db014bc..ddb7749 100644
--- a/.gitignore
+++ b/.gitignore
@@ -90,3 +90,4 @@ dist
 .yarn/unplugged
 .yarn/build-state.yml
 .pnp.*
+tests/output
diff --git a/package.json b/package.json
index 02869c7..2a4808f 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,7 @@
   "author": "TheoryOfNekomata <allan.crisostomo@outlook.com> (https://modal.sh)",
   "module": "dist/number-name.esm.js",
   "devDependencies": {
+    "@types/node": "^14.6.0",
     "fast-check": "^2.1.0",
     "husky": "^4.2.5",
     "tsdx": "^0.13.2",
diff --git a/src/Converter.ts b/src/Converter.ts
new file mode 100644
index 0000000..c440af6
--- /dev/null
+++ b/src/Converter.ts
@@ -0,0 +1,43 @@
+import NumberSystem from './NumberSystem'
+import ConverterStream from './ConverterStream'
+import { ReadStreamOptions, ConvertOptions } from './common'
+
+export default class Converter {
+  constructor(private readonly system: NumberSystem) {}
+
+  convert(value: string | number | bigint, options: ConvertOptions) {
+    let converted: string[] = []
+    switch (typeof value!) {
+      case 'string':
+        return ''
+      case 'bigint':
+      case 'number':
+        let current = value as number
+        let thousandPower = 0
+        while (current > 0) {
+          const hundreds = Math.floor((current % 1000) / 100)
+          const tens = Math.floor((current % 100) / 10)
+          const ones = Math.floor(current % 10)
+          if (!(ones === 0 && tens === 0 && hundreds === 0)) {
+            if (thousandPower > 0) {
+              const { scale = 'short' } = options
+              converted.unshift(this.system.getKiloName[scale!]!(thousandPower))
+            }
+            converted.unshift(this.system.getKiloCount(hundreds, tens, ones))
+          }
+
+          thousandPower = thousandPower + 1
+          current = Math.floor(current / 1000)
+        }
+        return converted.join(' ')
+      default:
+        break
+    }
+    throw TypeError('Invalid argument passed to value.')
+  }
+
+  readStream(options: ReadStreamOptions): ConverterStream {
+    const { scale = 'short', encoding = 'utf-8' } = options
+    return new ConverterStream(this.system, { scale, encoding })
+  }
+}
diff --git a/src/ConverterStream.ts b/src/ConverterStream.ts
new file mode 100644
index 0000000..6f70e52
--- /dev/null
+++ b/src/ConverterStream.ts
@@ -0,0 +1,45 @@
+import { Transform } from 'stream'
+import NumberSystem from './NumberSystem'
+import { ReadStreamOptions } from './common'
+
+export default class ConverterStream extends Transform {
+  private thousandPower: number = 0
+
+  constructor(private readonly system: NumberSystem, private readonly options: ReadStreamOptions) {
+    super()
+    this.thousandPower = 0
+  }
+
+  _transform(chunk: any, _encoding: BufferEncoding, callback: Function) {
+    const { scale, encoding } = this.options
+
+    const [ones = 0, tens = 0, hundreds = 0] = chunk
+      .toString(encoding!)
+      .split('')
+      .filter((s: string) => /[0-9]/.test(s))
+      .map((d: string) => Number(d)) // todo use encoding
+
+    if (!(ones === 0 && tens === 0 && hundreds === 0)) {
+      if (this.thousandPower > 0) {
+        this.push(
+          this.system.getKiloName[scale!]!(this.thousandPower)
+            .split('')
+            .reverse()
+            .join(''),
+        )
+        this.push(' ')
+      }
+      this.push(
+        this.system
+          .getKiloCount(hundreds, tens, ones)
+          .split('')
+          .reverse()
+          .join(''),
+      )
+      this.push(' ')
+    }
+
+    this.thousandPower = this.thousandPower + 1
+    callback()
+  }
+}
diff --git a/src/common/NumberSystem.ts b/src/NumberSystem.ts
similarity index 72%
rename from src/common/NumberSystem.ts
rename to src/NumberSystem.ts
index 0aa53ab..40ced05 100644
--- a/src/common/NumberSystem.ts
+++ b/src/NumberSystem.ts
@@ -2,9 +2,9 @@ export type GetKiloCount = (hundreds: number, tens: number, ones: number) => str
 export type GetKiloName = (thousandPower: number) => string
 
 export default interface NumberSystem {
-  getKiloCount: GetKiloCount,
+  getKiloCount: GetKiloCount
   getKiloName: {
-    short?: GetKiloName,
-    long?: GetKiloName,
+    short?: GetKiloName
+    long?: GetKiloName
   }
 }
diff --git a/src/NumberSystemNameTable.ts b/src/NumberSystemNameTable.ts
new file mode 100644
index 0000000..989e93c
--- /dev/null
+++ b/src/NumberSystemNameTable.ts
@@ -0,0 +1,14 @@
+export default interface NumberSystemNameTable {
+  units: string[10]
+  tenPlus: string[10]
+  tenTimes: string[10]
+  hundred: string
+  thousand: string
+  kiloSpecialUnits: string[10]
+  kiloUnits: string[10]
+  kiloTens: string[10]
+  kiloHundreds: string[10]
+  kiloThousand: string
+  kiloEvenSuffix: string
+  kiloOddSuffix: string
+}
diff --git a/src/common.ts b/src/common.ts
new file mode 100644
index 0000000..b867649
--- /dev/null
+++ b/src/common.ts
@@ -0,0 +1,11 @@
+export type Scale = 'long' | 'short'
+
+export interface ConvertOptions {
+  scale?: Scale
+}
+
+export interface StreamOptions {
+  encoding?: BufferEncoding
+}
+
+export type ReadStreamOptions = ConvertOptions & StreamOptions
diff --git a/src/common/NumberSystemNameTable.ts b/src/common/NumberSystemNameTable.ts
deleted file mode 100644
index 63a75dc..0000000
--- a/src/common/NumberSystemNameTable.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-export default interface NumberSystemNameTable {
-  units: string[10],
-  tenPlus: string[10],
-  tenTimes: string[10],
-  hundred: string,
-  thousand: string,
-  kiloSpecialUnits: string[10],
-  kiloUnits: string[10],
-  kiloTens: string[10],
-  kiloHundreds: string[10],
-  kiloThousand: string,
-  kiloEvenSuffix: string,
-  kiloOddSuffix: string,
-}
diff --git a/src/common/interfaces.ts b/src/common/interfaces.ts
deleted file mode 100644
index e69de29..0000000
diff --git a/src/index.ts b/src/index.ts
index d00a9c0..c3db9c4 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,3 @@
-export default () => {
-  throw Error('Not yet implemented!')
-}
+import Converter from './Converter'
+
+export default Converter
diff --git a/src/systems/de/base/hundredTimes.test.ts b/src/systems/de/base/hundredTimes.test.ts
index df8d2c5..9bc87d7 100644
--- a/src/systems/de/base/hundredTimes.test.ts
+++ b/src/systems/de/base/hundredTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'siebenhundert'}
   ${8}  | ${'800'} | ${'achthundert'}
   ${9}  | ${'900'} | ${'neunhundert'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundredTimes(value)).toBe(name)
 })
diff --git a/src/systems/de/base/hundredTimes.ts b/src/systems/de/base/hundredTimes.ts
index 9c9b14f..15097ef 100644
--- a/src/systems/de/base/hundredTimes.ts
+++ b/src/systems/de/base/hundredTimes.ts
@@ -9,13 +9,6 @@ interface HundredTimes {
  * @param {number} x100 - The number in the hundreds place.
  * @returns {string} The name of the number in the hundreds place.
  */
-const hundredTimes: HundredTimes = (x100) => (
-  x100 === 0
-    ? NAMES.units[0]
-    : [
-      NAMES.units[x100],
-      NAMES.hundred,
-    ].join('')
-)
+const hundredTimes: HundredTimes = (x100) => (x100 === 0 ? NAMES.units[0] : [NAMES.units[x100], NAMES.hundred].join(''))
 
 export default hundredTimes
diff --git a/src/systems/de/base/kilo/combiningPrefix.test.ts b/src/systems/de/base/kilo/combiningPrefix.test.ts
index 53ef7f6..03482fd 100644
--- a/src/systems/de/base/kilo/combiningPrefix.test.ts
+++ b/src/systems/de/base/kilo/combiningPrefix.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in hundreds place', () => {
       ${7}  | ${'7'}  | ${'septi'}
       ${8}  | ${'8'}  | ${'octi'}
       ${9}  | ${'9'}  | ${'noni'}
-    `('should return "$name" on $display', ({ value, name, }) => {
+    `('should return "$name" on $display', ({ value, name }) => {
       expect(combiningPrefix(0, 0, value)).toBe(name)
     })
   })
@@ -41,7 +41,7 @@ describe('on 0 in hundreds place', () => {
     ${7} | ${'septuaginti'}
     ${8} | ${'octoginti'}
     ${9} | ${'nonaginti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${tensName}
@@ -54,7 +54,7 @@ describe('on 0 in hundreds place', () => {
       ${7} | ${'septen' + tensName}
       ${8} | ${'octo' + tensName}
       ${9} | ${'novem' + tensName}
-    `(`should return "$display" for ${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(0, tens, ones)).toBe(display)
     })
   })
@@ -71,7 +71,7 @@ describe.each`
   ${7}     | ${'septingen'}
   ${8}     | ${'octingen'}
   ${9}     | ${'nongen'}
-`('on $hundreds in hundreds place', ({ hundreds, hundredsName, }) => {
+`('on $hundreds in hundreds place', ({ hundreds, hundredsName }) => {
   describe.each`
     tens | tensName
     ${0} | ${'ti'}
@@ -84,7 +84,7 @@ describe.each`
     ${7} | ${'septuaginti'}
     ${8} | ${'octoginti'}
     ${9} | ${'nonaginti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${hundredsName + tensName}
@@ -97,7 +97,7 @@ describe.each`
       ${7} | ${hundredsName + 'septen' + tensName}
       ${8} | ${hundredsName + 'octo' + tensName}
       ${9} | ${hundredsName + 'novem' + tensName}
-    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(hundreds, tens, ones)).toBe(display)
     })
   })
@@ -114,7 +114,7 @@ describe.each`
   ${7}             | ${'septingen'}
   ${8}             | ${'octingen'}
   ${9}             | ${'nongen'}
-`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName, }) => {
+`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName }) => {
   describe.each`
     tenThousands | tenThousandsName
     ${0}         | ${''}
@@ -127,7 +127,7 @@ describe.each`
     ${7}         | ${'septuagin'}
     ${8}         | ${'octogin'}
     ${9}         | ${'nonagin'}
-  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName, }) => {
+  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName }) => {
     test.each`
       thousands | display                                          | name
       ${0}      | ${hundredThousands + '' + tenThousands + '0000'} | ${hundredThousandsName + tenThousandsName + 'milliati'}
@@ -140,17 +140,9 @@ describe.each`
       ${7000}   | ${hundredThousands + '' + tenThousands + '7000'} | ${hundredThousandsName + 'septen' + tenThousandsName + 'milliati'}
       ${8000}   | ${hundredThousands + '' + tenThousands + '8000'} | ${hundredThousandsName + 'octo' + tenThousandsName + 'milliati'}
       ${9000}   | ${hundredThousands + '' + tenThousands + '9000'} | ${hundredThousandsName + 'novem' + tenThousandsName + 'milliati'}
-    `(`should return "$name" for $display`, ({ thousands, name, }) => {
-      const kiloHundreds = (
-        hundredThousands * 1000
-        + tenThousands * 100
-        + thousands / 100
-      )
-      expect(combiningPrefix(
-        kiloHundreds,
-        0,
-        0,
-      )).toBe(name)
+    `(`should return "$name" for $display`, ({ thousands, name }) => {
+      const kiloHundreds = hundredThousands * 1000 + tenThousands * 100 + thousands / 100
+      expect(combiningPrefix(kiloHundreds, 0, 0)).toBe(name)
     })
   })
 })
@@ -166,7 +158,7 @@ test.each`
   ${7}  | ${'7000000'} | ${'septenmilliamilliati'}
   ${8}  | ${'8000000'} | ${'octomilliamilliati'}
   ${9}  | ${'9000000'} | ${'novemmilliamilliati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10000, 0, 0)).toBe(name)
 })
 
@@ -181,7 +173,6 @@ test.each`
   ${7}  | ${'7007000'} | ${'septenmilliamilliaseptenmilliati'}
   ${8}  | ${'8008000'} | ${'octomilliamilliaoctomilliati'}
   ${9}  | ${'9009000'} | ${'novemmilliamillianovemmilliati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10010, 0, 0)).toBe(name)
 })
-
diff --git a/src/systems/de/base/kilo/combiningPrefix.ts b/src/systems/de/base/kilo/combiningPrefix.ts
index 32c5c96..7901b61 100644
--- a/src/systems/de/base/kilo/combiningPrefix.ts
+++ b/src/systems/de/base/kilo/combiningPrefix.ts
@@ -4,20 +4,10 @@ import tens from './tens'
 import hundreds from './hundreds'
 
 interface CombiningPrefix {
-  (
-    kiloHundreds: number,
-    kiloTens: number,
-    kiloOnes: number,
-    kiloPower?: number,
-  ): string,
+  (kiloHundreds: number, kiloTens: number, kiloOnes: number, kiloPower?: number): string
 }
 
-const combiningPrefix: CombiningPrefix = (
-  kiloHundredsRaw,
-  kiloTens,
-  kiloOnes,
-  kiloPower = 0,
-) => {
+const combiningPrefix: CombiningPrefix = (kiloHundredsRaw, kiloTens, kiloOnes, kiloPower = 0) => {
   let kiloHundreds = kiloHundredsRaw
   let prefix = ''
 
@@ -25,8 +15,8 @@ const combiningPrefix: CombiningPrefix = (
   if (isMillia) {
     prefix += combiningPrefix(
       Math.floor(kiloHundredsRaw / 1000),
-      Math.floor(kiloHundredsRaw / 100 % 10),
-      Math.floor(kiloHundredsRaw / 10 % 10),
+      Math.floor((kiloHundredsRaw / 100) % 10),
+      Math.floor((kiloHundredsRaw / 10) % 10),
       kiloPower + 1,
     )
     kiloHundreds = kiloHundredsRaw % 10
@@ -38,43 +28,18 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (
-    (
-      kiloPower > 0
-      && (
-        (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes > 1
-        )
-        || (
-          (
-            kiloHundreds > 0
-            || kiloTens > 0
-          )
-          && kiloOnes > 0
-        )
-        || (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes === 1
-          && prefix.endsWith(NAMES.kiloThousand)
-        )
-      )
-    )
+    kiloPower > 0 &&
+    ((kiloHundreds === 0 && kiloTens === 0 && kiloOnes > 1) ||
+      ((kiloHundreds > 0 || kiloTens > 0) && kiloOnes > 0) ||
+      (kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 1 && prefix.endsWith(NAMES.kiloThousand)))
   ) {
     // http://www.isthe.com/chongo/tech/math/number/howhigh.html
     // Section: Titanic size numbers < 10^3000003
-    prefix += ones(
-      kiloOnes,
-      false
-    )
+    prefix += ones(kiloOnes, false)
   }
   if (kiloPower === 0 && kiloOnes > 0) {
     const special = kiloHundreds === 0 && kiloTens === 0
-    prefix += ones(
-      kiloOnes,
-      special
-    )
+    prefix += ones(kiloOnes, special)
     if (special && [5, 6].includes(kiloOnes)) {
       prefix += 't'
     }
@@ -84,11 +49,7 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (kiloPower > 0) {
-    if (!(
-      kiloHundreds === 0
-      && kiloTens === 0
-      && kiloOnes === 0
-    )) {
+    if (!(kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 0)) {
       for (let p = 0; p < kiloPower; p += 1) {
         prefix += NAMES.kiloThousand
       }
@@ -96,11 +57,7 @@ const combiningPrefix: CombiningPrefix = (
     return prefix
   }
 
-  if (
-    (kiloHundreds === 0 && kiloTens > 1)
-    || (kiloHundreds > 0 && kiloTens !== 1)
-    || kiloHundredsRaw >= 10
-  ) {
+  if ((kiloHundreds === 0 && kiloTens > 1) || (kiloHundreds > 0 && kiloTens !== 1) || kiloHundredsRaw >= 10) {
     prefix += 't'
   }
   return prefix + 'i'
diff --git a/src/systems/de/base/kilo/hundreds.test.ts b/src/systems/de/base/kilo/hundreds.test.ts
index caa97dd..6d11420 100644
--- a/src/systems/de/base/kilo/hundreds.test.ts
+++ b/src/systems/de/base/kilo/hundreds.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'septingen'}
   ${8}  | ${'800'} | ${'octingen'}
   ${9}  | ${'900'} | ${'nongen'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundreds(value)).toBe(name)
 })
diff --git a/src/systems/de/base/kilo/hundreds.ts b/src/systems/de/base/kilo/hundreds.ts
index 7b261d2..9d24831 100644
--- a/src/systems/de/base/kilo/hundreds.ts
+++ b/src/systems/de/base/kilo/hundreds.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Hundreds {
-  (kiloHundreds: number): string,
+  (kiloHundreds: number): string
 }
 
 const hundreds: Hundreds = (kiloHundreds) => NAMES.kiloHundreds[kiloHundreds]
diff --git a/src/systems/de/base/kilo/ones.test.ts b/src/systems/de/base/kilo/ones.test.ts
index 8cf0aa4..31ec3af 100644
--- a/src/systems/de/base/kilo/ones.test.ts
+++ b/src/systems/de/base/kilo/ones.test.ts
@@ -25,7 +25,7 @@ describe('on ordinary units', () => {
     ${7}  | ${'7'}  | ${'septen'}
     ${8}  | ${'8'}  | ${'octo'}
     ${9}  | ${'9'}  | ${'novem'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, false)).toBe(name)
   })
 })
@@ -43,7 +43,7 @@ describe('on special units', () => {
     ${7}  | ${'7'}  | ${'sept'}
     ${8}  | ${'8'}  | ${'oct'}
     ${9}  | ${'9'}  | ${'non'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, true)).toBe(name)
   })
 })
diff --git a/src/systems/de/base/kilo/ones.ts b/src/systems/de/base/kilo/ones.ts
index 0e6fa8f..0b11d0d 100644
--- a/src/systems/de/base/kilo/ones.ts
+++ b/src/systems/de/base/kilo/ones.ts
@@ -1,13 +1,10 @@
 import NAMES from '../../names.json'
 
 interface Ones {
-  (kiloOnes: number, special: boolean): string,
+  (kiloOnes: number, special: boolean): string
 }
 
-const ones: Ones = (kiloOnes, special = false) => (
-  special
-    ? NAMES.kiloSpecialUnits[kiloOnes]
-    : NAMES.kiloUnits[kiloOnes]
-)
+const ones: Ones = (kiloOnes, special = false) =>
+  special ? NAMES.kiloSpecialUnits[kiloOnes] : NAMES.kiloUnits[kiloOnes]
 
 export default ones
diff --git a/src/systems/de/base/kilo/tens.test.ts b/src/systems/de/base/kilo/tens.test.ts
index f6984ac..9d678e0 100644
--- a/src/systems/de/base/kilo/tens.test.ts
+++ b/src/systems/de/base/kilo/tens.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'septuagin'}
   ${8}  | ${'80'} | ${'octogin'}
   ${9}  | ${'90'} | ${'nonagin'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tens(value)).toBe(name)
 })
diff --git a/src/systems/de/base/kilo/tens.ts b/src/systems/de/base/kilo/tens.ts
index bfe97e0..54f9975 100644
--- a/src/systems/de/base/kilo/tens.ts
+++ b/src/systems/de/base/kilo/tens.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Tens {
-  (kiloTens: number): string,
+  (kiloTens: number): string
 }
 
 const tens: Tens = (kiloTens) => NAMES.kiloTens[kiloTens]
diff --git a/src/systems/de/base/ones.test.ts b/src/systems/de/base/ones.test.ts
index 5c8b068..d242305 100644
--- a/src/systems/de/base/ones.test.ts
+++ b/src/systems/de/base/ones.test.ts
@@ -24,7 +24,6 @@ test.each`
   ${7}  | ${'7'}  | ${'sieben'}
   ${8}  | ${'8'}  | ${'acht'}
   ${9}  | ${'9'}  | ${'neun'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(ones(value)).toBe(name)
 })
-
diff --git a/src/systems/de/base/tenPlus.test.ts b/src/systems/de/base/tenPlus.test.ts
index 065fe62..6b1fe4a 100644
--- a/src/systems/de/base/tenPlus.test.ts
+++ b/src/systems/de/base/tenPlus.test.ts
@@ -24,6 +24,6 @@ test.each`
   ${7}  | ${'17'} | ${'siebzehn'}
   ${8}  | ${'18'} | ${'achtzehn'}
   ${9}  | ${'19'} | ${'neunzehn'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenPlus(value)).toBe(name)
 })
diff --git a/src/systems/de/base/tenTimes.test.ts b/src/systems/de/base/tenTimes.test.ts
index e259fd7..b4a76d1 100644
--- a/src/systems/de/base/tenTimes.test.ts
+++ b/src/systems/de/base/tenTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'siebzig'}
   ${8}  | ${'80'} | ${'achtzig'}
   ${9}  | ${'90'} | ${'neunzig'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenTimes(value)).toBe(name)
 })
diff --git a/src/systems/de/construct/tens.test.ts b/src/systems/de/construct/tens.test.ts
index 4560f59..0d7ff95 100644
--- a/src/systems/de/construct/tens.test.ts
+++ b/src/systems/de/construct/tens.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in tens place', () => {
     ${7} | ${'sieben'}
     ${8} | ${'acht'}
     ${9} | ${'neun'}
-  `(`should return "$onesName" for $ones`, ({ ones, onesName, }) => {
+  `(`should return "$onesName" for $ones`, ({ ones, onesName }) => {
     expect(tensFn(0, ones)).toBe(onesName)
   })
 })
@@ -43,35 +43,35 @@ describe('on 1 in tens place', () => {
     ${7} | ${'siebzehn'}
     ${8} | ${'achtzehn'}
     ${9} | ${'neunzehn'}
-  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName, }) => {
+  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName }) => {
     expect(tensFn(1, ones)).toBe(tenPlusName)
   })
 })
 
 describe.each`
-    tens | tensName
-    ${2} | ${'zwanzig'}
-    ${3} | ${'dreißig'}
-    ${4} | ${'vierzig'}
-    ${5} | ${'fünfzig'}
-    ${6} | ${'sechzig'}
-    ${7} | ${'siebzig'}
-    ${8} | ${'achtzig'}
-    ${9} | ${'neunzig'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  tens | tensName
+  ${2} | ${'zwanzig'}
+  ${3} | ${'dreißig'}
+  ${4} | ${'vierzig'}
+  ${5} | ${'fünfzig'}
+  ${6} | ${'sechzig'}
+  ${7} | ${'siebzig'}
+  ${8} | ${'achtzig'}
+  ${9} | ${'neunzig'}
+`('on $tens in tens place', ({ tens, tensName }) => {
   test.each`
-      ones | display
-      ${0} | ${'' + tensName}
-      ${1} | ${'einund' + tensName}
-      ${2} | ${'zweiund' + tensName}
-      ${3} | ${'dreiund' + tensName}
-      ${4} | ${'vierund' + tensName}
-      ${5} | ${'fünfund' + tensName}
-      ${6} | ${'sechsund' + tensName}
-      ${7} | ${'siebenund' + tensName}
-      ${8} | ${'achtund' + tensName}
-      ${9} | ${'neunund' + tensName}
-    `(`should return "$display" for ${tens}$ones`, ({ ones, display, }) => {
+    ones | display
+    ${0} | ${'' + tensName}
+    ${1} | ${'einund' + tensName}
+    ${2} | ${'zweiund' + tensName}
+    ${3} | ${'dreiund' + tensName}
+    ${4} | ${'vierund' + tensName}
+    ${5} | ${'fünfund' + tensName}
+    ${6} | ${'sechsund' + tensName}
+    ${7} | ${'siebenund' + tensName}
+    ${8} | ${'achtund' + tensName}
+    ${9} | ${'neunund' + tensName}
+  `(`should return "$display" for ${tens}$ones`, ({ ones, display }) => {
     expect(tensFn(tens, ones)).toBe(display)
   })
 })
diff --git a/src/systems/de/construct/tens.ts b/src/systems/de/construct/tens.ts
index 26cc522..124bf93 100644
--- a/src/systems/de/construct/tens.ts
+++ b/src/systems/de/construct/tens.ts
@@ -4,7 +4,7 @@ import tenPlus from '../base/tenPlus'
 import getBaseTenTimesName from '../base/tenTimes'
 
 interface Tens {
-  (x10: number, x1: number): string,
+  (x10: number, x1: number): string
 }
 
 const tens: Tens = (x10, x1) => {
@@ -20,16 +20,7 @@ const tens: Tens = (x10, x1) => {
       break
   }
 
-  return (
-    x1 > 0
-      ? [
-        ones(x1),
-        NAMES.and,
-        getBaseTenTimesName(x10),
-      ]
-        .join('')
-      : getBaseTenTimesName(x10)
-  )
+  return x1 > 0 ? [ones(x1), NAMES.and, getBaseTenTimesName(x10)].join('') : getBaseTenTimesName(x10)
 }
 
 export default tens
diff --git a/src/systems/de/getLongKiloName.test.ts b/src/systems/de/getLongKiloName.test.ts
index a55c463..7c4f621 100644
--- a/src/systems/de/getLongKiloName.test.ts
+++ b/src/systems/de/getLongKiloName.test.ts
@@ -34,7 +34,7 @@ test.each`
   ${17}         | ${'Octilliard'}
   ${18}         | ${'Nonillion'}
   ${19}         | ${'Nonilliard'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -49,7 +49,7 @@ test.each`
   ${140}        | ${'Septuagintillion'}
   ${160}        | ${'Octogintillion'}
   ${180}        | ${'Nonagintillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -64,7 +64,7 @@ test.each`
   ${1400}       | ${'Septingentillion'}
   ${1600}       | ${'Octingentillion'}
   ${1800}       | ${'Nongentillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -79,7 +79,7 @@ test.each`
   ${14000}      | ${'Septenmilliatillion'}
   ${16000}      | ${'Octomilliatillion'}
   ${18000}      | ${'Novemmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -94,7 +94,7 @@ test.each`
   ${140000}     | ${'Septuaginmilliatillion'}
   ${160000}     | ${'Octoginmilliatillion'}
   ${180000}     | ${'Nonaginmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -109,7 +109,7 @@ test.each`
   ${1400000}    | ${'Septingenmilliatillion'}
   ${1600000}    | ${'Octingenmilliatillion'}
   ${1800000}    | ${'Nongenmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -124,6 +124,6 @@ test.each`
   ${14000000}   | ${'Septenmilliamilliatillion'}
   ${16000000}   | ${'Octomilliamilliatillion'}
   ${18000000}   | ${'Novemmilliamilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
diff --git a/src/systems/de/getLongKiloName.ts b/src/systems/de/getLongKiloName.ts
index 1a78bda..a7c5db5 100644
--- a/src/systems/de/getLongKiloName.ts
+++ b/src/systems/de/getLongKiloName.ts
@@ -1,12 +1,10 @@
-import { GetKiloName, } from '../../common/NumberSystem'
+import { GetKiloName } from '../../NumberSystem'
 import NAMES from './names.json'
 import getKiloCombiningPrefix from './base/kilo/combiningPrefix'
 
-const capitalizeFirstLetter = (word: string) => (
-  word.slice(0, 1).toUpperCase() + word.slice(1)
-)
+const capitalizeFirstLetter = (word: string) => word.slice(0, 1).toUpperCase() + word.slice(1)
 
-const getLongKiloName: GetKiloName = thousandPower => {
+const getLongKiloName: GetKiloName = (thousandPower) => {
   if (thousandPower === 0) {
     return ''
   }
@@ -15,18 +13,12 @@ const getLongKiloName: GetKiloName = thousandPower => {
   }
   const kilo = thousandPower
   const kiloHundreds = Math.floor(kilo / 2 / 100)
-  const kiloTens = Math.floor(kilo / 2 / 10 % 10)
-  const kiloOnes = Math.floor(kilo / 2 % 10)
-  const kiloCombiningPrefix = getKiloCombiningPrefix(
-    kiloHundreds,
-    kiloTens,
-    kiloOnes
-  )
+  const kiloTens = Math.floor((kilo / 2 / 10) % 10)
+  const kiloOnes = Math.floor((kilo / 2) % 10)
+  const kiloCombiningPrefix = getKiloCombiningPrefix(kiloHundreds, kiloTens, kiloOnes)
 
   return capitalizeFirstLetter(
-    thousandPower % 2 === 0
-      ? kiloCombiningPrefix + NAMES.kiloEvenSuffix
-      : kiloCombiningPrefix + NAMES.kiloOddSuffix
+    thousandPower % 2 === 0 ? kiloCombiningPrefix + NAMES.kiloEvenSuffix : kiloCombiningPrefix + NAMES.kiloOddSuffix,
   )
 }
 
diff --git a/src/systems/en.ts b/src/systems/en.ts
index 55bdba6..975bd76 100644
--- a/src/systems/en.ts
+++ b/src/systems/en.ts
@@ -1,4 +1,4 @@
-import NumberSystem from '../common/NumberSystem'
+import NumberSystem from '../NumberSystem'
 import getKiloCount from './en/getKiloCount'
 import getLongKiloName from './en/getLongKiloName'
 import getShortKiloName from './en/getShortKiloName'
@@ -8,7 +8,7 @@ const en: NumberSystem = {
   getKiloName: {
     short: getShortKiloName,
     long: getLongKiloName,
-  }
+  },
 }
 
 export default en
diff --git a/src/systems/en/base/hundredTimes.test.ts b/src/systems/en/base/hundredTimes.test.ts
index f2b7d3e..92247a1 100644
--- a/src/systems/en/base/hundredTimes.test.ts
+++ b/src/systems/en/base/hundredTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'seven hundred'}
   ${8}  | ${'800'} | ${'eight hundred'}
   ${9}  | ${'900'} | ${'nine hundred'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundredTimes(value)).toBe(name)
 })
diff --git a/src/systems/en/base/hundredTimes.ts b/src/systems/en/base/hundredTimes.ts
index e13daf5..f3820a9 100644
--- a/src/systems/en/base/hundredTimes.ts
+++ b/src/systems/en/base/hundredTimes.ts
@@ -9,13 +9,7 @@ interface HundredTimes {
  * @param {number} x100 - The number in the hundreds place.
  * @returns {string} The name of the number in the hundreds place.
  */
-const hundredTimes: HundredTimes = (x100) => (
-  x100 === 0
-    ? NAMES.units[0]
-    : [
-      NAMES.units[x100],
-      NAMES.hundred,
-    ].join(' ')
-)
+const hundredTimes: HundredTimes = (x100) =>
+  x100 === 0 ? NAMES.units[0] : [NAMES.units[x100], NAMES.hundred].join(' ')
 
 export default hundredTimes
diff --git a/src/systems/en/base/kilo/combiningPrefix.test.ts b/src/systems/en/base/kilo/combiningPrefix.test.ts
index 53ef7f6..03482fd 100644
--- a/src/systems/en/base/kilo/combiningPrefix.test.ts
+++ b/src/systems/en/base/kilo/combiningPrefix.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in hundreds place', () => {
       ${7}  | ${'7'}  | ${'septi'}
       ${8}  | ${'8'}  | ${'octi'}
       ${9}  | ${'9'}  | ${'noni'}
-    `('should return "$name" on $display', ({ value, name, }) => {
+    `('should return "$name" on $display', ({ value, name }) => {
       expect(combiningPrefix(0, 0, value)).toBe(name)
     })
   })
@@ -41,7 +41,7 @@ describe('on 0 in hundreds place', () => {
     ${7} | ${'septuaginti'}
     ${8} | ${'octoginti'}
     ${9} | ${'nonaginti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${tensName}
@@ -54,7 +54,7 @@ describe('on 0 in hundreds place', () => {
       ${7} | ${'septen' + tensName}
       ${8} | ${'octo' + tensName}
       ${9} | ${'novem' + tensName}
-    `(`should return "$display" for ${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(0, tens, ones)).toBe(display)
     })
   })
@@ -71,7 +71,7 @@ describe.each`
   ${7}     | ${'septingen'}
   ${8}     | ${'octingen'}
   ${9}     | ${'nongen'}
-`('on $hundreds in hundreds place', ({ hundreds, hundredsName, }) => {
+`('on $hundreds in hundreds place', ({ hundreds, hundredsName }) => {
   describe.each`
     tens | tensName
     ${0} | ${'ti'}
@@ -84,7 +84,7 @@ describe.each`
     ${7} | ${'septuaginti'}
     ${8} | ${'octoginti'}
     ${9} | ${'nonaginti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${hundredsName + tensName}
@@ -97,7 +97,7 @@ describe.each`
       ${7} | ${hundredsName + 'septen' + tensName}
       ${8} | ${hundredsName + 'octo' + tensName}
       ${9} | ${hundredsName + 'novem' + tensName}
-    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(hundreds, tens, ones)).toBe(display)
     })
   })
@@ -114,7 +114,7 @@ describe.each`
   ${7}             | ${'septingen'}
   ${8}             | ${'octingen'}
   ${9}             | ${'nongen'}
-`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName, }) => {
+`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName }) => {
   describe.each`
     tenThousands | tenThousandsName
     ${0}         | ${''}
@@ -127,7 +127,7 @@ describe.each`
     ${7}         | ${'septuagin'}
     ${8}         | ${'octogin'}
     ${9}         | ${'nonagin'}
-  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName, }) => {
+  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName }) => {
     test.each`
       thousands | display                                          | name
       ${0}      | ${hundredThousands + '' + tenThousands + '0000'} | ${hundredThousandsName + tenThousandsName + 'milliati'}
@@ -140,17 +140,9 @@ describe.each`
       ${7000}   | ${hundredThousands + '' + tenThousands + '7000'} | ${hundredThousandsName + 'septen' + tenThousandsName + 'milliati'}
       ${8000}   | ${hundredThousands + '' + tenThousands + '8000'} | ${hundredThousandsName + 'octo' + tenThousandsName + 'milliati'}
       ${9000}   | ${hundredThousands + '' + tenThousands + '9000'} | ${hundredThousandsName + 'novem' + tenThousandsName + 'milliati'}
-    `(`should return "$name" for $display`, ({ thousands, name, }) => {
-      const kiloHundreds = (
-        hundredThousands * 1000
-        + tenThousands * 100
-        + thousands / 100
-      )
-      expect(combiningPrefix(
-        kiloHundreds,
-        0,
-        0,
-      )).toBe(name)
+    `(`should return "$name" for $display`, ({ thousands, name }) => {
+      const kiloHundreds = hundredThousands * 1000 + tenThousands * 100 + thousands / 100
+      expect(combiningPrefix(kiloHundreds, 0, 0)).toBe(name)
     })
   })
 })
@@ -166,7 +158,7 @@ test.each`
   ${7}  | ${'7000000'} | ${'septenmilliamilliati'}
   ${8}  | ${'8000000'} | ${'octomilliamilliati'}
   ${9}  | ${'9000000'} | ${'novemmilliamilliati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10000, 0, 0)).toBe(name)
 })
 
@@ -181,7 +173,6 @@ test.each`
   ${7}  | ${'7007000'} | ${'septenmilliamilliaseptenmilliati'}
   ${8}  | ${'8008000'} | ${'octomilliamilliaoctomilliati'}
   ${9}  | ${'9009000'} | ${'novemmilliamillianovemmilliati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10010, 0, 0)).toBe(name)
 })
-
diff --git a/src/systems/en/base/kilo/combiningPrefix.ts b/src/systems/en/base/kilo/combiningPrefix.ts
index 32c5c96..7901b61 100644
--- a/src/systems/en/base/kilo/combiningPrefix.ts
+++ b/src/systems/en/base/kilo/combiningPrefix.ts
@@ -4,20 +4,10 @@ import tens from './tens'
 import hundreds from './hundreds'
 
 interface CombiningPrefix {
-  (
-    kiloHundreds: number,
-    kiloTens: number,
-    kiloOnes: number,
-    kiloPower?: number,
-  ): string,
+  (kiloHundreds: number, kiloTens: number, kiloOnes: number, kiloPower?: number): string
 }
 
-const combiningPrefix: CombiningPrefix = (
-  kiloHundredsRaw,
-  kiloTens,
-  kiloOnes,
-  kiloPower = 0,
-) => {
+const combiningPrefix: CombiningPrefix = (kiloHundredsRaw, kiloTens, kiloOnes, kiloPower = 0) => {
   let kiloHundreds = kiloHundredsRaw
   let prefix = ''
 
@@ -25,8 +15,8 @@ const combiningPrefix: CombiningPrefix = (
   if (isMillia) {
     prefix += combiningPrefix(
       Math.floor(kiloHundredsRaw / 1000),
-      Math.floor(kiloHundredsRaw / 100 % 10),
-      Math.floor(kiloHundredsRaw / 10 % 10),
+      Math.floor((kiloHundredsRaw / 100) % 10),
+      Math.floor((kiloHundredsRaw / 10) % 10),
       kiloPower + 1,
     )
     kiloHundreds = kiloHundredsRaw % 10
@@ -38,43 +28,18 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (
-    (
-      kiloPower > 0
-      && (
-        (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes > 1
-        )
-        || (
-          (
-            kiloHundreds > 0
-            || kiloTens > 0
-          )
-          && kiloOnes > 0
-        )
-        || (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes === 1
-          && prefix.endsWith(NAMES.kiloThousand)
-        )
-      )
-    )
+    kiloPower > 0 &&
+    ((kiloHundreds === 0 && kiloTens === 0 && kiloOnes > 1) ||
+      ((kiloHundreds > 0 || kiloTens > 0) && kiloOnes > 0) ||
+      (kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 1 && prefix.endsWith(NAMES.kiloThousand)))
   ) {
     // http://www.isthe.com/chongo/tech/math/number/howhigh.html
     // Section: Titanic size numbers < 10^3000003
-    prefix += ones(
-      kiloOnes,
-      false
-    )
+    prefix += ones(kiloOnes, false)
   }
   if (kiloPower === 0 && kiloOnes > 0) {
     const special = kiloHundreds === 0 && kiloTens === 0
-    prefix += ones(
-      kiloOnes,
-      special
-    )
+    prefix += ones(kiloOnes, special)
     if (special && [5, 6].includes(kiloOnes)) {
       prefix += 't'
     }
@@ -84,11 +49,7 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (kiloPower > 0) {
-    if (!(
-      kiloHundreds === 0
-      && kiloTens === 0
-      && kiloOnes === 0
-    )) {
+    if (!(kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 0)) {
       for (let p = 0; p < kiloPower; p += 1) {
         prefix += NAMES.kiloThousand
       }
@@ -96,11 +57,7 @@ const combiningPrefix: CombiningPrefix = (
     return prefix
   }
 
-  if (
-    (kiloHundreds === 0 && kiloTens > 1)
-    || (kiloHundreds > 0 && kiloTens !== 1)
-    || kiloHundredsRaw >= 10
-  ) {
+  if ((kiloHundreds === 0 && kiloTens > 1) || (kiloHundreds > 0 && kiloTens !== 1) || kiloHundredsRaw >= 10) {
     prefix += 't'
   }
   return prefix + 'i'
diff --git a/src/systems/en/base/kilo/hundreds.test.ts b/src/systems/en/base/kilo/hundreds.test.ts
index caa97dd..6d11420 100644
--- a/src/systems/en/base/kilo/hundreds.test.ts
+++ b/src/systems/en/base/kilo/hundreds.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'septingen'}
   ${8}  | ${'800'} | ${'octingen'}
   ${9}  | ${'900'} | ${'nongen'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundreds(value)).toBe(name)
 })
diff --git a/src/systems/en/base/kilo/hundreds.ts b/src/systems/en/base/kilo/hundreds.ts
index 7b261d2..9d24831 100644
--- a/src/systems/en/base/kilo/hundreds.ts
+++ b/src/systems/en/base/kilo/hundreds.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Hundreds {
-  (kiloHundreds: number): string,
+  (kiloHundreds: number): string
 }
 
 const hundreds: Hundreds = (kiloHundreds) => NAMES.kiloHundreds[kiloHundreds]
diff --git a/src/systems/en/base/kilo/ones.test.ts b/src/systems/en/base/kilo/ones.test.ts
index 8cf0aa4..31ec3af 100644
--- a/src/systems/en/base/kilo/ones.test.ts
+++ b/src/systems/en/base/kilo/ones.test.ts
@@ -25,7 +25,7 @@ describe('on ordinary units', () => {
     ${7}  | ${'7'}  | ${'septen'}
     ${8}  | ${'8'}  | ${'octo'}
     ${9}  | ${'9'}  | ${'novem'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, false)).toBe(name)
   })
 })
@@ -43,7 +43,7 @@ describe('on special units', () => {
     ${7}  | ${'7'}  | ${'sept'}
     ${8}  | ${'8'}  | ${'oct'}
     ${9}  | ${'9'}  | ${'non'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, true)).toBe(name)
   })
 })
diff --git a/src/systems/en/base/kilo/ones.ts b/src/systems/en/base/kilo/ones.ts
index 0e6fa8f..0b11d0d 100644
--- a/src/systems/en/base/kilo/ones.ts
+++ b/src/systems/en/base/kilo/ones.ts
@@ -1,13 +1,10 @@
 import NAMES from '../../names.json'
 
 interface Ones {
-  (kiloOnes: number, special: boolean): string,
+  (kiloOnes: number, special: boolean): string
 }
 
-const ones: Ones = (kiloOnes, special = false) => (
-  special
-    ? NAMES.kiloSpecialUnits[kiloOnes]
-    : NAMES.kiloUnits[kiloOnes]
-)
+const ones: Ones = (kiloOnes, special = false) =>
+  special ? NAMES.kiloSpecialUnits[kiloOnes] : NAMES.kiloUnits[kiloOnes]
 
 export default ones
diff --git a/src/systems/en/base/kilo/tens.test.ts b/src/systems/en/base/kilo/tens.test.ts
index f6984ac..9d678e0 100644
--- a/src/systems/en/base/kilo/tens.test.ts
+++ b/src/systems/en/base/kilo/tens.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'septuagin'}
   ${8}  | ${'80'} | ${'octogin'}
   ${9}  | ${'90'} | ${'nonagin'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tens(value)).toBe(name)
 })
diff --git a/src/systems/en/base/kilo/tens.ts b/src/systems/en/base/kilo/tens.ts
index bfe97e0..54f9975 100644
--- a/src/systems/en/base/kilo/tens.ts
+++ b/src/systems/en/base/kilo/tens.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Tens {
-  (kiloTens: number): string,
+  (kiloTens: number): string
 }
 
 const tens: Tens = (kiloTens) => NAMES.kiloTens[kiloTens]
diff --git a/src/systems/en/base/ones.test.ts b/src/systems/en/base/ones.test.ts
index 6f722ab..baae111 100644
--- a/src/systems/en/base/ones.test.ts
+++ b/src/systems/en/base/ones.test.ts
@@ -24,7 +24,6 @@ test.each`
   ${7}  | ${'7'}  | ${'seven'}
   ${8}  | ${'8'}  | ${'eight'}
   ${9}  | ${'9'}  | ${'nine'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(ones(value)).toBe(name)
 })
-
diff --git a/src/systems/en/base/tenPlus.test.ts b/src/systems/en/base/tenPlus.test.ts
index a8cf9ca..66e6c47 100644
--- a/src/systems/en/base/tenPlus.test.ts
+++ b/src/systems/en/base/tenPlus.test.ts
@@ -24,6 +24,6 @@ test.each`
   ${7}  | ${'17'} | ${'seventeen'}
   ${8}  | ${'18'} | ${'eighteen'}
   ${9}  | ${'19'} | ${'nineteen'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenPlus(value)).toBe(name)
 })
diff --git a/src/systems/en/base/tenTimes.test.ts b/src/systems/en/base/tenTimes.test.ts
index fef4f8b..4f7dc33 100644
--- a/src/systems/en/base/tenTimes.test.ts
+++ b/src/systems/en/base/tenTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'seventy'}
   ${8}  | ${'80'} | ${'eighty'}
   ${9}  | ${'90'} | ${'ninety'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenTimes(value)).toBe(name)
 })
diff --git a/src/systems/en/construct/tens.test.ts b/src/systems/en/construct/tens.test.ts
index 636a52d..6afe128 100644
--- a/src/systems/en/construct/tens.test.ts
+++ b/src/systems/en/construct/tens.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in tens place', () => {
     ${7} | ${'seven'}
     ${8} | ${'eight'}
     ${9} | ${'nine'}
-  `(`should return "$onesName" for $ones`, ({ ones, onesName, }) => {
+  `(`should return "$onesName" for $ones`, ({ ones, onesName }) => {
     expect(tensFn(0, ones)).toBe(onesName)
   })
 })
@@ -43,38 +43,35 @@ describe('on 1 in tens place', () => {
     ${7} | ${'seventeen'}
     ${8} | ${'eighteen'}
     ${9} | ${'nineteen'}
-  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName, }) => {
+  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName }) => {
     expect(tensFn(1, ones)).toBe(tenPlusName)
   })
 })
 
 describe.each`
-    tens | tensName
-    ${2} | ${'twenty'}
-    ${3} | ${'thirty'}
-    ${4} | ${'forty'}
-    ${5} | ${'fifty'}
-    ${6} | ${'sixty'}
-    ${7} | ${'seventy'}
-    ${8} | ${'eighty'}
-    ${9} | ${'ninety'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  tens | tensName
+  ${2} | ${'twenty'}
+  ${3} | ${'thirty'}
+  ${4} | ${'forty'}
+  ${5} | ${'fifty'}
+  ${6} | ${'sixty'}
+  ${7} | ${'seventy'}
+  ${8} | ${'eighty'}
+  ${9} | ${'ninety'}
+`('on $tens in tens place', ({ tens, tensName }) => {
   test.each`
-      ones | onesName
-      ${0} | ${''}
-      ${1} | ${' one'}
-      ${2} | ${' two'}
-      ${3} | ${' three'}
-      ${4} | ${' four'}
-      ${5} | ${' five'}
-      ${6} | ${' six'}
-      ${7} | ${' seven'}
-      ${8} | ${' eight'}
-      ${9} | ${' nine'}
-    `(`should return "${tensName}$onesName" for ${tens}$ones`, ({ ones, onesName, }) => {
-    expect(tensFn(tens, ones)).toBe([
-      tensName,
-      onesName
-    ].join(''))
+    ones | onesName
+    ${0} | ${''}
+    ${1} | ${' one'}
+    ${2} | ${' two'}
+    ${3} | ${' three'}
+    ${4} | ${' four'}
+    ${5} | ${' five'}
+    ${6} | ${' six'}
+    ${7} | ${' seven'}
+    ${8} | ${' eight'}
+    ${9} | ${' nine'}
+  `(`should return "${tensName}$onesName" for ${tens}$ones`, ({ ones, onesName }) => {
+    expect(tensFn(tens, ones)).toBe([tensName, onesName].join(''))
   })
 })
diff --git a/src/systems/en/construct/tens.ts b/src/systems/en/construct/tens.ts
index 04e53fc..62ddba4 100644
--- a/src/systems/en/construct/tens.ts
+++ b/src/systems/en/construct/tens.ts
@@ -3,7 +3,7 @@ import tenPlus from '../base/tenPlus'
 import getBaseTenTimesName from '../base/tenTimes'
 
 interface Tens {
-  (x10: number, x1: number): string,
+  (x10: number, x1: number): string
 }
 
 const tens: Tens = (x10, x1) => {
@@ -19,15 +19,7 @@ const tens: Tens = (x10, x1) => {
       break
   }
 
-  return (
-    x1 > 0
-      ? [
-        getBaseTenTimesName(x10),
-        ones(x1),
-      ]
-      .join(' ')
-      : getBaseTenTimesName(x10)
-  )
+  return x1 > 0 ? [getBaseTenTimesName(x10), ones(x1)].join(' ') : getBaseTenTimesName(x10)
 }
 
 export default tens
diff --git a/src/systems/en/getKiloCount.test.ts b/src/systems/en/getKiloCount.test.ts
index 495cc71..c388a97 100644
--- a/src/systems/en/getKiloCount.test.ts
+++ b/src/systems/en/getKiloCount.test.ts
@@ -23,7 +23,7 @@ describe.each`
   ${7}     | ${'seven hundred'}
   ${8}     | ${'eight hundred'}
   ${9}     | ${'nine hundred'}
-`('on $hundreds in hundreds place', ({ hundreds, hundredsName, }) => {
+`('on $hundreds in hundreds place', ({ hundreds, hundredsName }) => {
   describe('on 0 in tens place', () => {
     test.each`
       ones | onesName
@@ -37,13 +37,10 @@ describe.each`
       ${7} | ${' seven'}
       ${8} | ${' eight'}
       ${9} | ${' nine'}
-    `(`should return "${hundredsName}$onesName" for ${hundreds}0$ones`, ({ ones, onesName, }) => {
-        expect(getKiloCount(hundreds, 0, ones)).toBe([
-          hundredsName,
-          onesName
-        ].join(''))
-      })
+    `(`should return "${hundredsName}$onesName" for ${hundreds}0$ones`, ({ ones, onesName }) => {
+      expect(getKiloCount(hundreds, 0, ones)).toBe([hundredsName, onesName].join(''))
     })
+  })
 
   describe('on 1 in tens place', () => {
     test.each`
@@ -58,13 +55,10 @@ describe.each`
       ${7} | ${' seventeen'}
       ${8} | ${' eighteen'}
       ${9} | ${' nineteen'}
-    `(`should return "${hundredsName}$tenPlusName" for ${hundreds}1$ones`, ({ ones, tenPlusName, }) => {
-        expect(getKiloCount(hundreds, 1, ones)).toBe([
-          hundredsName,
-          tenPlusName
-        ].join(''))
-      })
+    `(`should return "${hundredsName}$tenPlusName" for ${hundreds}1$ones`, ({ ones, tenPlusName }) => {
+      expect(getKiloCount(hundreds, 1, ones)).toBe([hundredsName, tenPlusName].join(''))
     })
+  })
 
   describe.each`
     tens | tensName
@@ -76,7 +70,7 @@ describe.each`
     ${7} | ${' seventy'}
     ${8} | ${' eighty'}
     ${9} | ${' ninety'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | onesName
       ${0} | ${''}
@@ -89,12 +83,8 @@ describe.each`
       ${7} | ${' seven'}
       ${8} | ${' eight'}
       ${9} | ${' nine'}
-    `(`should return "${hundredsName}${tensName}$onesName" for ${hundreds}${tens}$ones`, ({ ones, onesName, }) => {
-      expect(getKiloCount(hundreds, tens, ones)).toBe([
-        hundredsName,
-        tensName,
-        onesName
-      ].join(''))
+    `(`should return "${hundredsName}${tensName}$onesName" for ${hundreds}${tens}$ones`, ({ ones, onesName }) => {
+      expect(getKiloCount(hundreds, tens, ones)).toBe([hundredsName, tensName, onesName].join(''))
     })
   })
 })
diff --git a/src/systems/en/getKiloCount.ts b/src/systems/en/getKiloCount.ts
index c4c84f9..3f6fd3e 100644
--- a/src/systems/en/getKiloCount.ts
+++ b/src/systems/en/getKiloCount.ts
@@ -1,12 +1,8 @@
-import { GetKiloCount, } from '../../common/NumberSystem'
+import { GetKiloCount } from '../../NumberSystem'
 import constructTens from './construct/tens'
 import hundredTimes from './base/hundredTimes'
 
-const getKiloCount: GetKiloCount = (
-  x100,
-  x10,
-  x1
-) => {
+const getKiloCount: GetKiloCount = (x100, x10, x1) => {
   if (x100 < 1) {
     return constructTens(x10, x1)
   }
@@ -14,11 +10,7 @@ const getKiloCount: GetKiloCount = (
   if (x10 === 0 && x1 === 0) {
     return hundredTimes(x100)
   }
-  return [
-    hundredTimes(x100),
-    constructTens(x10, x1),
-  ]
-    .join(' ')
+  return [hundredTimes(x100), constructTens(x10, x1)].join(' ')
 }
 
 export default getKiloCount
diff --git a/src/systems/en/getLongKiloName.test.ts b/src/systems/en/getLongKiloName.test.ts
index 44d12c7..e37c4f6 100644
--- a/src/systems/en/getLongKiloName.test.ts
+++ b/src/systems/en/getLongKiloName.test.ts
@@ -34,7 +34,7 @@ test.each`
   ${17}         | ${'thousand octillion'}
   ${18}         | ${'nonillion'}
   ${19}         | ${'thousand nonillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -49,7 +49,7 @@ test.each`
   ${140}        | ${'septuagintillion'}
   ${160}        | ${'octogintillion'}
   ${180}        | ${'nonagintillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -64,7 +64,7 @@ test.each`
   ${1400}       | ${'septingentillion'}
   ${1600}       | ${'octingentillion'}
   ${1800}       | ${'nongentillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -79,7 +79,7 @@ test.each`
   ${14000}      | ${'septenmilliatillion'}
   ${16000}      | ${'octomilliatillion'}
   ${18000}      | ${'novemmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -94,7 +94,7 @@ test.each`
   ${140000}     | ${'septuaginmilliatillion'}
   ${160000}     | ${'octoginmilliatillion'}
   ${180000}     | ${'nonaginmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -109,7 +109,7 @@ test.each`
   ${1400000}    | ${'septingenmilliatillion'}
   ${1600000}    | ${'octingenmilliatillion'}
   ${1800000}    | ${'nongenmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -124,6 +124,6 @@ test.each`
   ${14000000}   | ${'septenmilliamilliatillion'}
   ${16000000}   | ${'octomilliamilliatillion'}
   ${18000000}   | ${'novemmilliamilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
diff --git a/src/systems/en/getLongKiloName.ts b/src/systems/en/getLongKiloName.ts
index e4d290e..b558937 100644
--- a/src/systems/en/getLongKiloName.ts
+++ b/src/systems/en/getLongKiloName.ts
@@ -1,8 +1,8 @@
-import { GetKiloName, } from '../../common/NumberSystem'
+import { GetKiloName } from '../../NumberSystem'
 import NAMES from './names.json'
 import getKiloCombiningPrefix from './base/kilo/combiningPrefix'
 
-const getLongKiloName: GetKiloName = thousandPower => {
+const getLongKiloName: GetKiloName = (thousandPower) => {
   if (thousandPower === 0) {
     return ''
   }
@@ -11,19 +11,11 @@ const getLongKiloName: GetKiloName = thousandPower => {
   }
   const kilo = thousandPower
   const kiloHundreds = Math.floor(kilo / 2 / 100)
-  const kiloTens = Math.floor(kilo / 2 / 10 % 10)
-  const kiloOnes = Math.floor(kilo / 2 % 10)
-  const baseKiloName = getKiloCombiningPrefix(
-    kiloHundreds,
-    kiloTens,
-    kiloOnes
-  ) + NAMES.kiloEvenSuffix
+  const kiloTens = Math.floor((kilo / 2 / 10) % 10)
+  const kiloOnes = Math.floor((kilo / 2) % 10)
+  const baseKiloName = getKiloCombiningPrefix(kiloHundreds, kiloTens, kiloOnes) + NAMES.kiloEvenSuffix
 
-  return (
-    thousandPower % 2 === 0
-      ? baseKiloName
-      : NAMES.thousand + ' ' + baseKiloName
-  )
+  return thousandPower % 2 === 0 ? baseKiloName : NAMES.thousand + ' ' + baseKiloName
 }
 
 export default getLongKiloName
diff --git a/src/systems/en/getShortKiloName.test.ts b/src/systems/en/getShortKiloName.test.ts
index 1047bd9..75524e7 100644
--- a/src/systems/en/getShortKiloName.test.ts
+++ b/src/systems/en/getShortKiloName.test.ts
@@ -25,7 +25,7 @@ test.each`
   ${8}          | ${'septillion'}
   ${9}          | ${'octillion'}
   ${10}         | ${'nonillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -40,7 +40,7 @@ test.each`
   ${71}         | ${'septuagintillion'}
   ${81}         | ${'octogintillion'}
   ${91}         | ${'nonagintillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -55,7 +55,7 @@ test.each`
   ${701}        | ${'septingentillion'}
   ${801}        | ${'octingentillion'}
   ${901}        | ${'nongentillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -70,7 +70,7 @@ test.each`
   ${7001}       | ${'septenmilliatillion'}
   ${8001}       | ${'octomilliatillion'}
   ${9001}       | ${'novemmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -85,7 +85,7 @@ test.each`
   ${70001}      | ${'septuaginmilliatillion'}
   ${80001}      | ${'octoginmilliatillion'}
   ${90001}      | ${'nonaginmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -100,7 +100,7 @@ test.each`
   ${700001}     | ${'septingenmilliatillion'}
   ${800001}     | ${'octingenmilliatillion'}
   ${900001}     | ${'nongenmilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
 
@@ -115,6 +115,6 @@ test.each`
   ${7000001}    | ${'septenmilliamilliatillion'}
   ${8000001}    | ${'octomilliamilliatillion'}
   ${9000001}    | ${'novemmilliamilliatillion'}
-`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower, }) => {
+`('should return "$name" for 1000^$thousandPower', ({ name, thousandPower }) => {
   expect(getKiloName(thousandPower)).toBe(name)
 })
diff --git a/src/systems/en/getShortKiloName.ts b/src/systems/en/getShortKiloName.ts
index 2fd635e..0ddc40d 100644
--- a/src/systems/en/getShortKiloName.ts
+++ b/src/systems/en/getShortKiloName.ts
@@ -1,8 +1,8 @@
-import { GetKiloName, } from '../../common/NumberSystem'
+import { GetKiloName } from '../../NumberSystem'
 import NAMES from './names.json'
 import getKiloCombiningPrefix from './base/kilo/combiningPrefix'
 
-const getKiloName: GetKiloName = thousandPower => {
+const getKiloName: GetKiloName = (thousandPower) => {
   if (thousandPower === 0) {
     return ''
   }
@@ -11,14 +11,10 @@ const getKiloName: GetKiloName = thousandPower => {
   }
   const kilo = thousandPower - 1
   const kiloHundreds = Math.floor(kilo / 100)
-  const kiloTens = Math.floor(kilo / 10 % 10)
+  const kiloTens = Math.floor((kilo / 10) % 10)
   const kiloOnes = Math.floor(kilo % 10)
 
-  return getKiloCombiningPrefix(
-    kiloHundreds,
-    kiloTens,
-    kiloOnes
-  ) + NAMES.kiloEvenSuffix
+  return getKiloCombiningPrefix(kiloHundreds, kiloTens, kiloOnes) + NAMES.kiloEvenSuffix
 }
 
 export default getKiloName
diff --git a/src/systems/tl/base/hundredTimes.test.ts b/src/systems/tl/base/hundredTimes.test.ts
index 6bd35b7..7880c39 100644
--- a/src/systems/tl/base/hundredTimes.test.ts
+++ b/src/systems/tl/base/hundredTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'pitongdaan'}
   ${8}  | ${'800'} | ${'walongdaan'}
   ${9}  | ${'900'} | ${'siyamnaraan'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundredTimes(value)).toBe(name)
 })
diff --git a/src/systems/tl/base/hundredTimes.ts b/src/systems/tl/base/hundredTimes.ts
index aa4e6bf..25df6cd 100644
--- a/src/systems/tl/base/hundredTimes.ts
+++ b/src/systems/tl/base/hundredTimes.ts
@@ -48,12 +48,7 @@ const hundredTimes: HundredTimes = (x100) => {
       break
   }
 
-  return [
-    hundredFactorCombining,
-    infix,
-    hundredSuffixCombining,
-  ]
-    .join('')
+  return [hundredFactorCombining, infix, hundredSuffixCombining].join('')
 }
 
 export default hundredTimes
diff --git a/src/systems/tl/base/kilo/combiningPrefix.test.ts b/src/systems/tl/base/kilo/combiningPrefix.test.ts
index f969164..53361b0 100644
--- a/src/systems/tl/base/kilo/combiningPrefix.test.ts
+++ b/src/systems/tl/base/kilo/combiningPrefix.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in hundreds place', () => {
       ${7}  | ${'7'}  | ${'septi'}
       ${8}  | ${'8'}  | ${'okti'}
       ${9}  | ${'9'}  | ${'noni'}
-    `('should return "$name" on $display', ({ value, name, }) => {
+    `('should return "$name" on $display', ({ value, name }) => {
       expect(combiningPrefix(0, 0, value)).toBe(name)
     })
   })
@@ -41,7 +41,7 @@ describe('on 0 in hundreds place', () => {
     ${7} | ${'septuwahinti'}
     ${8} | ${'oktohinti'}
     ${9} | ${'nonahinti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${tensName}
@@ -54,7 +54,7 @@ describe('on 0 in hundreds place', () => {
       ${7} | ${'septen' + tensName}
       ${8} | ${'okto' + tensName}
       ${9} | ${'nobem' + tensName}
-    `(`should return "$display" for ${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(0, tens, ones)).toBe(display)
     })
   })
@@ -71,7 +71,7 @@ describe.each`
   ${7}     | ${'septinghen'}
   ${8}     | ${'oktinghen'}
   ${9}     | ${'nonghen'}
-`('on $hundreds in hundreds place', ({ hundreds, hundredsName, }) => {
+`('on $hundreds in hundreds place', ({ hundreds, hundredsName }) => {
   describe.each`
     tens | tensName
     ${0} | ${'ti'}
@@ -84,7 +84,7 @@ describe.each`
     ${7} | ${'septuwahinti'}
     ${8} | ${'oktohinti'}
     ${9} | ${'nonahinti'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     test.each`
       ones | display
       ${0} | ${hundredsName + tensName}
@@ -97,7 +97,7 @@ describe.each`
       ${7} | ${hundredsName + 'septen' + tensName}
       ${8} | ${hundredsName + 'okto' + tensName}
       ${9} | ${hundredsName + 'nobem' + tensName}
-    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display, }) => {
+    `(`should return "$display" for ${hundreds}${tens}$ones`, ({ ones, display }) => {
       expect(combiningPrefix(hundreds, tens, ones)).toBe(display)
     })
   })
@@ -114,7 +114,7 @@ describe.each`
   ${7}             | ${'septinghen'}
   ${8}             | ${'oktinghen'}
   ${9}             | ${'nonghen'}
-`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName, }) => {
+`('on $hundredThousands in hundred thousands place', ({ hundredThousands, hundredThousandsName }) => {
   describe.each`
     tenThousands | tenThousandsName
     ${0}         | ${''}
@@ -127,7 +127,7 @@ describe.each`
     ${7}         | ${'septuwahin'}
     ${8}         | ${'oktohin'}
     ${9}         | ${'nonahin'}
-  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName, }) => {
+  `('on $tenThousands in ten thousands place', ({ tenThousands, tenThousandsName }) => {
     test.each`
       thousands | display                                          | name
       ${0}      | ${hundredThousands + '' + tenThousands + '0000'} | ${hundredThousandsName + tenThousandsName + 'milyati'}
@@ -140,17 +140,9 @@ describe.each`
       ${7000}   | ${hundredThousands + '' + tenThousands + '7000'} | ${hundredThousandsName + 'septen' + tenThousandsName + 'milyati'}
       ${8000}   | ${hundredThousands + '' + tenThousands + '8000'} | ${hundredThousandsName + 'okto' + tenThousandsName + 'milyati'}
       ${9000}   | ${hundredThousands + '' + tenThousands + '9000'} | ${hundredThousandsName + 'nobem' + tenThousandsName + 'milyati'}
-    `(`should return "$name" for $display`, ({ thousands, name, }) => {
-      const kiloHundreds = (
-        hundredThousands * 1000
-        + tenThousands * 100
-        + thousands / 100
-      )
-      expect(combiningPrefix(
-        kiloHundreds,
-        0,
-        0,
-      )).toBe(name)
+    `(`should return "$name" for $display`, ({ thousands, name }) => {
+      const kiloHundreds = hundredThousands * 1000 + tenThousands * 100 + thousands / 100
+      expect(combiningPrefix(kiloHundreds, 0, 0)).toBe(name)
     })
   })
 })
@@ -166,7 +158,7 @@ it.each`
   ${7}  | ${'7000000'} | ${'septenmilyamilyati'}
   ${8}  | ${'8000000'} | ${'oktomilyamilyati'}
   ${9}  | ${'9000000'} | ${'nobemmilyamilyati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10000, 0, 0)).toBe(name)
 })
 
@@ -181,7 +173,6 @@ it.each`
   ${7}  | ${'7007000'} | ${'septenmilyamilyaseptenmilyati'}
   ${8}  | ${'8008000'} | ${'oktomilyamilyaoktomilyati'}
   ${9}  | ${'9009000'} | ${'nobemmilyamilyanobemmilyati'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(combiningPrefix(value * 10010, 0, 0)).toBe(name)
 })
-
diff --git a/src/systems/tl/base/kilo/combiningPrefix.ts b/src/systems/tl/base/kilo/combiningPrefix.ts
index 32c5c96..7901b61 100644
--- a/src/systems/tl/base/kilo/combiningPrefix.ts
+++ b/src/systems/tl/base/kilo/combiningPrefix.ts
@@ -4,20 +4,10 @@ import tens from './tens'
 import hundreds from './hundreds'
 
 interface CombiningPrefix {
-  (
-    kiloHundreds: number,
-    kiloTens: number,
-    kiloOnes: number,
-    kiloPower?: number,
-  ): string,
+  (kiloHundreds: number, kiloTens: number, kiloOnes: number, kiloPower?: number): string
 }
 
-const combiningPrefix: CombiningPrefix = (
-  kiloHundredsRaw,
-  kiloTens,
-  kiloOnes,
-  kiloPower = 0,
-) => {
+const combiningPrefix: CombiningPrefix = (kiloHundredsRaw, kiloTens, kiloOnes, kiloPower = 0) => {
   let kiloHundreds = kiloHundredsRaw
   let prefix = ''
 
@@ -25,8 +15,8 @@ const combiningPrefix: CombiningPrefix = (
   if (isMillia) {
     prefix += combiningPrefix(
       Math.floor(kiloHundredsRaw / 1000),
-      Math.floor(kiloHundredsRaw / 100 % 10),
-      Math.floor(kiloHundredsRaw / 10 % 10),
+      Math.floor((kiloHundredsRaw / 100) % 10),
+      Math.floor((kiloHundredsRaw / 10) % 10),
       kiloPower + 1,
     )
     kiloHundreds = kiloHundredsRaw % 10
@@ -38,43 +28,18 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (
-    (
-      kiloPower > 0
-      && (
-        (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes > 1
-        )
-        || (
-          (
-            kiloHundreds > 0
-            || kiloTens > 0
-          )
-          && kiloOnes > 0
-        )
-        || (
-          kiloHundreds === 0
-          && kiloTens === 0
-          && kiloOnes === 1
-          && prefix.endsWith(NAMES.kiloThousand)
-        )
-      )
-    )
+    kiloPower > 0 &&
+    ((kiloHundreds === 0 && kiloTens === 0 && kiloOnes > 1) ||
+      ((kiloHundreds > 0 || kiloTens > 0) && kiloOnes > 0) ||
+      (kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 1 && prefix.endsWith(NAMES.kiloThousand)))
   ) {
     // http://www.isthe.com/chongo/tech/math/number/howhigh.html
     // Section: Titanic size numbers < 10^3000003
-    prefix += ones(
-      kiloOnes,
-      false
-    )
+    prefix += ones(kiloOnes, false)
   }
   if (kiloPower === 0 && kiloOnes > 0) {
     const special = kiloHundreds === 0 && kiloTens === 0
-    prefix += ones(
-      kiloOnes,
-      special
-    )
+    prefix += ones(kiloOnes, special)
     if (special && [5, 6].includes(kiloOnes)) {
       prefix += 't'
     }
@@ -84,11 +49,7 @@ const combiningPrefix: CombiningPrefix = (
   }
 
   if (kiloPower > 0) {
-    if (!(
-      kiloHundreds === 0
-      && kiloTens === 0
-      && kiloOnes === 0
-    )) {
+    if (!(kiloHundreds === 0 && kiloTens === 0 && kiloOnes === 0)) {
       for (let p = 0; p < kiloPower; p += 1) {
         prefix += NAMES.kiloThousand
       }
@@ -96,11 +57,7 @@ const combiningPrefix: CombiningPrefix = (
     return prefix
   }
 
-  if (
-    (kiloHundreds === 0 && kiloTens > 1)
-    || (kiloHundreds > 0 && kiloTens !== 1)
-    || kiloHundredsRaw >= 10
-  ) {
+  if ((kiloHundreds === 0 && kiloTens > 1) || (kiloHundreds > 0 && kiloTens !== 1) || kiloHundredsRaw >= 10) {
     prefix += 't'
   }
   return prefix + 'i'
diff --git a/src/systems/tl/base/kilo/hundreds.test.ts b/src/systems/tl/base/kilo/hundreds.test.ts
index 58d7a83..1c90ab5 100644
--- a/src/systems/tl/base/kilo/hundreds.test.ts
+++ b/src/systems/tl/base/kilo/hundreds.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'700'} | ${'septinghen'}
   ${8}  | ${'800'} | ${'oktinghen'}
   ${9}  | ${'900'} | ${'nonghen'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(hundreds(value)).toBe(name)
 })
diff --git a/src/systems/tl/base/kilo/hundreds.ts b/src/systems/tl/base/kilo/hundreds.ts
index 7b261d2..9d24831 100644
--- a/src/systems/tl/base/kilo/hundreds.ts
+++ b/src/systems/tl/base/kilo/hundreds.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Hundreds {
-  (kiloHundreds: number): string,
+  (kiloHundreds: number): string
 }
 
 const hundreds: Hundreds = (kiloHundreds) => NAMES.kiloHundreds[kiloHundreds]
diff --git a/src/systems/tl/base/kilo/ones.test.ts b/src/systems/tl/base/kilo/ones.test.ts
index cbe3ab4..df46e8a 100644
--- a/src/systems/tl/base/kilo/ones.test.ts
+++ b/src/systems/tl/base/kilo/ones.test.ts
@@ -25,7 +25,7 @@ describe('on ordinary units', () => {
     ${7}  | ${'7'}  | ${'septen'}
     ${8}  | ${'8'}  | ${'okto'}
     ${9}  | ${'9'}  | ${'nobem'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, false)).toBe(name)
   })
 })
@@ -43,7 +43,7 @@ describe('on special units', () => {
     ${7}  | ${'7'}  | ${'sept'}
     ${8}  | ${'8'}  | ${'okt'}
     ${9}  | ${'9'}  | ${'non'}
-  `('should return "$name" on $display', ({ value, name, }) => {
+  `('should return "$name" on $display', ({ value, name }) => {
     expect(ones(value, true)).toBe(name)
   })
 })
diff --git a/src/systems/tl/base/kilo/ones.ts b/src/systems/tl/base/kilo/ones.ts
index 0e6fa8f..0b11d0d 100644
--- a/src/systems/tl/base/kilo/ones.ts
+++ b/src/systems/tl/base/kilo/ones.ts
@@ -1,13 +1,10 @@
 import NAMES from '../../names.json'
 
 interface Ones {
-  (kiloOnes: number, special: boolean): string,
+  (kiloOnes: number, special: boolean): string
 }
 
-const ones: Ones = (kiloOnes, special = false) => (
-  special
-    ? NAMES.kiloSpecialUnits[kiloOnes]
-    : NAMES.kiloUnits[kiloOnes]
-)
+const ones: Ones = (kiloOnes, special = false) =>
+  special ? NAMES.kiloSpecialUnits[kiloOnes] : NAMES.kiloUnits[kiloOnes]
 
 export default ones
diff --git a/src/systems/tl/base/kilo/tens.test.ts b/src/systems/tl/base/kilo/tens.test.ts
index 02fab9c..f3bc3e4 100644
--- a/src/systems/tl/base/kilo/tens.test.ts
+++ b/src/systems/tl/base/kilo/tens.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'septuwahin'}
   ${8}  | ${'80'} | ${'oktohin'}
   ${9}  | ${'90'} | ${'nonahin'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tens(value)).toBe(name)
 })
diff --git a/src/systems/tl/base/kilo/tens.ts b/src/systems/tl/base/kilo/tens.ts
index bfe97e0..54f9975 100644
--- a/src/systems/tl/base/kilo/tens.ts
+++ b/src/systems/tl/base/kilo/tens.ts
@@ -1,7 +1,7 @@
 import NAMES from '../../names.json'
 
 interface Tens {
-  (kiloTens: number): string,
+  (kiloTens: number): string
 }
 
 const tens: Tens = (kiloTens) => NAMES.kiloTens[kiloTens]
diff --git a/src/systems/tl/base/ones.test.ts b/src/systems/tl/base/ones.test.ts
index 4a4d2f6..1fbb274 100644
--- a/src/systems/tl/base/ones.test.ts
+++ b/src/systems/tl/base/ones.test.ts
@@ -24,7 +24,6 @@ test.each`
   ${7}  | ${'7'}  | ${'pito'}
   ${8}  | ${'8'}  | ${'walo'}
   ${9}  | ${'9'}  | ${'siyam'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(ones(value)).toBe(name)
 })
-
diff --git a/src/systems/tl/base/tenPlus.test.ts b/src/systems/tl/base/tenPlus.test.ts
index 9dbb4b5..059a853 100644
--- a/src/systems/tl/base/tenPlus.test.ts
+++ b/src/systems/tl/base/tenPlus.test.ts
@@ -24,6 +24,6 @@ test.each`
   ${7}  | ${'17'} | ${'labimpito'}
   ${8}  | ${'18'} | ${'labingwalo'}
   ${9}  | ${'19'} | ${'labinsiyam'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenPlus(value)).toBe(name)
 })
diff --git a/src/systems/tl/base/tenTimes.test.ts b/src/systems/tl/base/tenTimes.test.ts
index 03e0e3f..0eaa21a 100644
--- a/src/systems/tl/base/tenTimes.test.ts
+++ b/src/systems/tl/base/tenTimes.test.ts
@@ -23,6 +23,6 @@ test.each`
   ${7}  | ${'70'} | ${'pitumpu'}
   ${8}  | ${'80'} | ${'walumpu'}
   ${9}  | ${'90'} | ${'siyamnapu'}
-`('should return "$name" on $display', ({ value, name, }) => {
+`('should return "$name" on $display', ({ value, name }) => {
   expect(tenTimes(value)).toBe(name)
 })
diff --git a/src/systems/tl/construct/tens.test.ts b/src/systems/tl/construct/tens.test.ts
index 8daf0a9..7295695 100644
--- a/src/systems/tl/construct/tens.test.ts
+++ b/src/systems/tl/construct/tens.test.ts
@@ -25,7 +25,7 @@ describe('on 0 in tens place', () => {
     ${7} | ${'pito'}
     ${8} | ${'walo'}
     ${9} | ${'siyam'}
-  `(`should return "$onesName" for $ones`, ({ ones, onesName, }) => {
+  `(`should return "$onesName" for $ones`, ({ ones, onesName }) => {
     expect(tensFn(0, ones)).toBe(onesName)
   })
 })
@@ -43,38 +43,35 @@ describe('on 1 in tens place', () => {
     ${7} | ${'labimpito'}
     ${8} | ${'labingwalo'}
     ${9} | ${'labinsiyam'}
-  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName, }) => {
+  `(`should return "$tenPlusName" for 1$ones`, ({ ones, tenPlusName }) => {
     expect(tensFn(1, ones)).toBe(tenPlusName)
   })
 })
 
 describe.each`
-    tens | tensName
-    ${2} | ${'dalawampu'}
-    ${3} | ${'tatlumpu'}
-    ${4} | ${'apatnapu'}
-    ${5} | ${'limampu'}
-    ${6} | ${'animnapu'}
-    ${7} | ${'pitumpu'}
-    ${8} | ${'walumpu'}
-    ${9} | ${'siyamnapu'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  tens | tensName
+  ${2} | ${'dalawampu'}
+  ${3} | ${'tatlumpu'}
+  ${4} | ${'apatnapu'}
+  ${5} | ${'limampu'}
+  ${6} | ${'animnapu'}
+  ${7} | ${'pitumpu'}
+  ${8} | ${'walumpu'}
+  ${9} | ${'siyamnapu'}
+`('on $tens in tens place', ({ tens, tensName }) => {
   test.each`
-      ones | onesName
-      ${0} | ${''}
-      ${1} | ${'\'t isa'}
-      ${2} | ${'\'t dalawa'}
-      ${3} | ${'\'t tatlo'}
-      ${4} | ${'\'t apat'}
-      ${5} | ${'\'t lima'}
-      ${6} | ${'\'t anim'}
-      ${7} | ${'\'t pito'}
-      ${8} | ${'\'t walo'}
-      ${9} | ${'\'t siyam'}
-    `(`should return "${tensName}$onesName" for ${tens}$ones`, ({ ones, onesName, }) => {
-    expect(tensFn(tens, ones)).toBe([
-      tensName,
-      onesName
-    ].join(''))
+    ones | onesName
+    ${0} | ${''}
+    ${1} | ${"'t isa"}
+    ${2} | ${"'t dalawa"}
+    ${3} | ${"'t tatlo"}
+    ${4} | ${"'t apat"}
+    ${5} | ${"'t lima"}
+    ${6} | ${"'t anim"}
+    ${7} | ${"'t pito"}
+    ${8} | ${"'t walo"}
+    ${9} | ${"'t siyam"}
+  `(`should return "${tensName}$onesName" for ${tens}$ones`, ({ ones, onesName }) => {
+    expect(tensFn(tens, ones)).toBe([tensName, onesName].join(''))
   })
 })
diff --git a/src/systems/tl/construct/tens.ts b/src/systems/tl/construct/tens.ts
index 5651632..178670a 100644
--- a/src/systems/tl/construct/tens.ts
+++ b/src/systems/tl/construct/tens.ts
@@ -4,7 +4,7 @@ import tenPlus from '../base/tenPlus'
 import getBaseTenTimesName from '../base/tenTimes'
 
 interface Tens {
-  (x10: number, x1: number): string,
+  (x10: number, x1: number): string
 }
 
 const tens: Tens = (x10, x1) => {
@@ -20,18 +20,7 @@ const tens: Tens = (x10, x1) => {
       break
   }
 
-  return (
-    x1 > 0
-      ? [
-        getBaseTenTimesName(x10),
-        "'",
-        NAMES.and.slice(1),
-        ' ',
-        ones(x1),
-      ]
-        .join('')
-      : getBaseTenTimesName(x10)
-  )
+  return x1 > 0 ? [getBaseTenTimesName(x10), "'", NAMES.and.slice(1), ' ', ones(x1)].join('') : getBaseTenTimesName(x10)
 }
 
 export default tens
diff --git a/src/systems/tl/getKiloCount.test.ts b/src/systems/tl/getKiloCount.test.ts
index 3a51dc9..c843238 100644
--- a/src/systems/tl/getKiloCount.test.ts
+++ b/src/systems/tl/getKiloCount.test.ts
@@ -23,7 +23,7 @@ describe.each`
   ${7}     | ${'pitongdaan'}
   ${8}     | ${'walongdaan'}
   ${9}     | ${'siyamnaraan'}
-`('on $hundreds in hundreds place', ({ hundreds, hundredsName, }) => {
+`('on $hundreds in hundreds place', ({ hundreds, hundredsName }) => {
   describe('on 0 in tens place', () => {
     test.each`
       ones | onesName
@@ -37,13 +37,10 @@ describe.each`
       ${7} | ${' at pito'}
       ${8} | ${' at walo'}
       ${9} | ${' at siyam'}
-    `(`should return "${hundredsName}$onesName" for ${hundreds}0$ones`, ({ ones, onesName, }) => {
-        expect(getKiloCount(hundreds, 0, ones)).toBe([
-          hundredsName,
-          onesName
-        ].join(''))
-      })
+    `(`should return "${hundredsName}$onesName" for ${hundreds}0$ones`, ({ ones, onesName }) => {
+      expect(getKiloCount(hundreds, 0, ones)).toBe([hundredsName, onesName].join(''))
     })
+  })
 
   describe('on 1 in tens place', () => {
     test.each`
@@ -58,13 +55,10 @@ describe.each`
       ${7} | ${' labimpito'}
       ${8} | ${' labingwalo'}
       ${9} | ${' labinsiyam'}
-    `(`should return "${hundredsName}$tenPlusName" for ${hundreds}1$ones`, ({ ones, tenPlusName, }) => {
-        expect(getKiloCount(hundreds, 1, ones)).toBe([
-          hundredsName,
-          tenPlusName
-        ].join(''))
-      })
+    `(`should return "${hundredsName}$tenPlusName" for ${hundreds}1$ones`, ({ ones, tenPlusName }) => {
+      expect(getKiloCount(hundreds, 1, ones)).toBe([hundredsName, tenPlusName].join(''))
     })
+  })
 
   describe.each`
     tens | tensName
@@ -76,31 +70,24 @@ describe.each`
     ${7} | ${' pitumpu'}
     ${8} | ${' walumpu'}
     ${9} | ${' siyamnapu'}
-  `('on $tens in tens place', ({ tens, tensName, }) => {
+  `('on $tens in tens place', ({ tens, tensName }) => {
     it(`should return "${hundredsName} at${tensName}" for ${hundreds}${tens}0`, () => {
-      expect(getKiloCount(hundreds, tens, 0)).toBe([
-        hundredsName,
-        tensName,
-      ].join(' at'))
+      expect(getKiloCount(hundreds, tens, 0)).toBe([hundredsName, tensName].join(' at'))
     })
 
     test.each`
       ones | onesName
-      ${1} | ${'\'t isa'}
-      ${2} | ${'\'t dalawa'}
-      ${3} | ${'\'t tatlo'}
-      ${4} | ${'\'t apat'}
-      ${5} | ${'\'t lima'}
-      ${6} | ${'\'t anim'}
-      ${7} | ${'\'t pito'}
-      ${8} | ${'\'t walo'}
-      ${9} | ${'\'t siyam'}
-    `(`should return "${hundredsName}${tensName}$onesName" for ${hundreds}${tens}$ones`, ({ ones, onesName, }) => {
-      expect(getKiloCount(hundreds, tens, ones)).toBe([
-        hundredsName,
-        tensName,
-        onesName
-      ].join(''))
+      ${1} | ${"'t isa"}
+      ${2} | ${"'t dalawa"}
+      ${3} | ${"'t tatlo"}
+      ${4} | ${"'t apat"}
+      ${5} | ${"'t lima"}
+      ${6} | ${"'t anim"}
+      ${7} | ${"'t pito"}
+      ${8} | ${"'t walo"}
+      ${9} | ${"'t siyam"}
+    `(`should return "${hundredsName}${tensName}$onesName" for ${hundreds}${tens}$ones`, ({ ones, onesName }) => {
+      expect(getKiloCount(hundreds, tens, ones)).toBe([hundredsName, tensName, onesName].join(''))
     })
   })
 })
diff --git a/src/systems/tl/getKiloCount.ts b/src/systems/tl/getKiloCount.ts
index 585fe54..e35f683 100644
--- a/src/systems/tl/getKiloCount.ts
+++ b/src/systems/tl/getKiloCount.ts
@@ -1,13 +1,9 @@
 import NAMES from './names.json'
-import { GetKiloCount, } from '../../common/NumberSystem'
+import { GetKiloCount } from '../../NumberSystem'
 import constructTens from './construct/tens'
 import hundredTimes from './base/hundredTimes'
 
-const getKiloCount: GetKiloCount = (
-  x100,
-  x10,
-  x1
-) => {
+const getKiloCount: GetKiloCount = (x100, x10, x1) => {
   if (x100 < 1) {
     return constructTens(x10, x1)
   }
@@ -16,26 +12,12 @@ const getKiloCount: GetKiloCount = (
     if (x1 === 0) {
       return hundredTimes(x100)
     }
-    return [
-      hundredTimes(x100),
-      NAMES.and,
-      constructTens(0, x1),
-    ]
-      .join(' ')
+    return [hundredTimes(x100), NAMES.and, constructTens(0, x1)].join(' ')
   }
   if (x1 === 0) {
-    return [
-      hundredTimes(x100),
-      NAMES.and,
-      constructTens(x10, x1),
-    ]
-      .join(' ')
+    return [hundredTimes(x100), NAMES.and, constructTens(x10, x1)].join(' ')
   }
-  return [
-    hundredTimes(x100),
-    constructTens(x10, x1),
-  ]
-    .join(' ')
+  return [hundredTimes(x100), constructTens(x10, x1)].join(' ')
 }
 
 export default getKiloCount
diff --git a/tests/Converter.test.ts b/tests/Converter.test.ts
new file mode 100644
index 0000000..f73c35e
--- /dev/null
+++ b/tests/Converter.test.ts
@@ -0,0 +1,54 @@
+import fs from 'fs'
+import Converter from '../src'
+import English from '../src/systems/en'
+
+describe.each`
+  name         | system     | scale
+  ${'English'} | ${English} | ${'short'}
+  ${'English'} | ${English} | ${'long'}
+`('$name ($scale count)', ({ system, scale, }) => {
+  let converter: Converter
+
+  beforeAll(() => {
+    converter = new Converter(system)
+  })
+
+  describe('on values', () => {
+    test.each`
+    value        | name
+    ${1000000}   | ${'one million'}
+    ${123456789} | ${'one hundred twenty three million four hundred fifty six thousand seven hundred eighty nine'}
+  `('should parse $value as $name', ({ value, name, }) => {
+      expect(converter.convert(value, { scale })).toBe(name)
+    })
+  })
+
+  describe('on streams', () => {
+    const ENCODING = 'utf-8'
+
+    test.each([
+      'million.txt'
+    ])('should correctly parse a stream', async (filename) => {
+      const inputStream = fs.createReadStream(
+        `./tests/input/${filename}`,
+        {
+          encoding: ENCODING,
+          highWaterMark: 3, // this is required to parse kilos correctly
+        }
+      )
+      const readStream = converter.readStream({
+        scale,
+        encoding: ENCODING
+      })
+      inputStream
+        .pipe(readStream)
+        .pipe(fs.createWriteStream(`./tests/output/${filename}`))
+
+      return new Promise((resolve) => {
+        readStream.on('end', () => {
+          resolve('Hello')
+        })
+      })
+    })
+  })
+})
diff --git a/tests/input/million.txt b/tests/input/million.txt
new file mode 100644
index 0000000..762357d
--- /dev/null
+++ b/tests/input/million.txt
@@ -0,0 +1 @@
+987000321
diff --git a/yarn.lock b/yarn.lock
index cd4e925..a79f65a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1155,6 +1155,11 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-14.0.27.tgz#a151873af5a5e851b51b3b065c9e63390a9e0eb1"
   integrity sha512-kVrqXhbclHNHGu9ztnAwSncIgJv/FaxmzXJvGXNdcCpV1b8u1/Mi6z6m0vwy0LzKeXFTPLH0NzwmoJ3fNCIq0g==
 
+"@types/node@^14.6.0":
+  version "14.6.0"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-14.6.0.tgz#7d4411bf5157339337d7cff864d9ff45f177b499"
+  integrity sha512-mikldZQitV94akrc4sCcSjtJfsTKt4p+e/s0AGscVA6XArQ9kFclP+ZiYUMnq987rc6QlYxXv/EivqlfSLxpKA==
+
 "@types/parse-json@^4.0.0":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"