How to Write Out USD Currency Amounts of Money in Words, Dollars and Cents, in (US) American English, Steps
1. How to convert amounts of money, without decimals, to US American English words?
To write an integer number we must know the place value of each digit.
For example, the number 1,234,567 has a 1 in the millions place, a 2 in the hundred thousands, a 3 in the ten thousands place, a 4 in the thousands place, a 5 in the hundreds place, a 6 in the tens place, and a 7 in the ones place.
1,234,567 in words is:
= one millions (1,000,000) + two hundred thousands (200,000) + three ten thousands (30,000) + four thousands (4,000) + five hundreds (500) + six tens (60) + seven ones (7)
= one million + two hundred thousands + thirty thousand + four thousand + five hundred + sixty + seven
= one million + (two hundred + thirty + four) thousand + five hundred + sixty + seven
= one million + two hundred thirty-four thousand + five hundred + sixty-seven
= one million two hundred thirty-four thousand five hundred sixty-seven.
So, 1,234,567$ = one million two hundred thirty-four thousand five hundred sixty-seven dollars.
1: Note the hyphen (or the minus sign) in "thirty-four" and "sixty-seven" above. Technically, it's correct to hyphenate compound numbers between twenty-one, 21, and ninety-nine, 99.
2: Placement of word "and": in American English do not use the word "and" after "hundred", "thousand" or "million". So, it is "one million two hundred thirty-four thousand five hundred sixty-seven" and not "one million and two hundred thirty-four thousand and five hundred and sixty-seven", though you may hear a lot of people using the last form, informally. On the contrary, the "and" word is always used in British English.
2. The United States issues paper currency and coins to pay for purchases, taxes, and debts:
Paper Money. The seven denominations of US currency in production are: $1 one dollar, $2 two dollar, $5 five dollar, $10 ten dollar, $20 twenty dollar, $50 fifty dollar and $100 one hundred dollar notes.
Coins. The United States issues several denominations, with the most common being: 1¢ (one cent = 0.01 dollars), 5¢ (five cents = 0.05 dollars), 10¢ (ten cents = 0.1 dollars), 25¢ (twenty-five cents = 0.25 dollars), 50¢ (fifty cents = 0.5 dollars) and $1 (one dollar).
Rounding off: with the smallest denomination of US curency being 1¢ (1 cent = 0.01 dollars) it means that we cannot have currency amounts with more than two decimals. If calculations give you amounts of money that have more than two decimals, then you have to round those numbers off to two decimals. If the third decimal is 5 or more, then round it up, if it is 4 or less, then round it down. Ex: 2.432 ≈ 2.43; 12.595 ≈ 12.60; 25.4949 ≈ 25.49; 5.6051 ≈ 5.61; 5.666666 ≈ 5.67; 5.333333 ≈ 5.33.
How to read a decimal number that represents an amount of money: the number before the decimal mark (to the left) is the dollar amount and the number after the decimal mark (to the right) is the cent amount. Examples below.
429.75$ = four hundred twenty-nine dollars + seventy-five cents. 1,300.5$ = one thousand three hundred dollars + fifty cents. 0.01$ = one cent = a penny. 0.05$ = five cents = a nickel. 0.1$ = ten cents = a dime. 0.25$ = twenty-five cents = a quarter. 0.5$ = fifty cents = half dollar (not so common a coin).