## How to write out numbers in words in (US) American English

### 1. How to convert natural numbers (positive integers) to (US) American English words, how to write them out (spell them out)?

#### 1.1. To know how to write a number in words we must know the place value of each digit.

- For example, the number 12,345 has a 1 in the ten thousands place, a 2 in the thousands place, a 3 in the hundreds place, a 4 in the tens place and a 5 in the ones place.
- 12,345 in words =
- = one ten thousands (10,000) + two thousands (2,000) + three hundreds (300) + four tens (40) + five ones
- = ten thousands (10,000) + two thousands (2,000) + three hundreds (300) + four tens (40) + five ones
- = ten thousand + two thousand + three hundred + forty + five
**= (ten + two) thousand + three hundred + forty-five**- = twelve thousand + three hundred + forty-five
- = just remove the plus sign, +, and get the number written out in words
- = twelve thousand three hundred forty-five.

### 2. When to write out numbers in words?

- Spell out all numbers beginning a sentence, "Forty years ago,..." Not "40 years ago,...".
- The Chicago Manual of Style calls for the numbers zero through one hundred to be written out - this would include forms like "one hundred million".
- Using words to write short numbers makes your writing look clean and classy. In handwriting, words are easy to read and hard to mistake for each other. Writing longer numbers as words isn't as useful, but it's good practice while you're learning.
- Otherwise, clarity should matter, for example when two numbers are used in a row allways spell one out: "They needed five 2-foot copper pipes to finish the job. There were 15 six-foot tall men on the basketball team roster.".
- Be consistent within a sentence, phrase... Do not write "... one million people..." and "... 1,000,000 cars..."; stick to one or another, not both.