Writing a number in words
Words for numbers follow a few fixed rules. Numbers from 21 to 99 are written with a hyphen between the tens and the ones: twenty-one, ninety-nine. The words hundred, thousand and million stay singular after a number: two hundred, five thousand, never two hundreds. Zero is written as zero. A decimal point is read as the word point, and the digits after it are read one at a time, so 3.14 is three point one four, not three point fourteen.
British and American English differ on one thing. British style puts and after hundreds: one hundred and five, one thousand and one, one million three hundred and twenty. American style usually leaves it out: one hundred five. Both are understood everywhere, so the choice is about house style. The switch Write and changes it. Hyphens can be turned off if your style guide wants twenty one.
Cheque amounts
On a cheque the amount is written in words as well as in numbers, because words are harder to change than digits, and in many places the words are the amount that counts if the two disagree. The usual layout is the whole amount in words, then the cents as a fraction of 100: One thousand two hundred thirty-four and 56/100 dollars. The other style spells the cents out: One thousand two hundred thirty-four dollars and fifty-six cents.
Amounts with more than two decimal places are rounded half up to the nearest cent, and the result tells you when that happened, so 1.005 becomes 1.01 and 999.999 becomes one thousand. The Japanese yen has no cents in everyday use, so yen amounts are rounded to a whole number. Choose Other to type the name of any currency in the plural, for example pesos and centavos. A trailing s is dropped for a singular amount.
Check what your bank asks for, such as the word only at the end, which this tool can add. A cheque amount cannot be negative, so a minus sign gives an error.
Ordinals
An ordinal says where something is in a sequence: first, second, third. Most are made by adding th to the cardinal number (fourth, sixth, tenth), with a few irregular ones: first, second, third, fifth, eighth, ninth and twelfth. A number ending in y changes it to ie before th, so twenty becomes twentieth. In a longer number only the last word changes: twenty-first, one hundred first, one thousandth.
Next to the words, the tool shows the number with its short ending: 1st, 2nd, 3rd and 4th. Numbers ending in 11, 12 and 13 use th (11th, 112th), even though they end in 1 or 2. An ordinal needs zero or a positive whole number.
Big numbers, and billion
Names for big numbers are in the short scale used in English today: a billion is 1,000,000,000 (a thousand million) and a trillion is 10 to the power 12. The names run through quadrillion, quintillion and sextillion up to vigintillion (10 to the power 63), which is the last group the tool names. That makes 66 digits the longest whole number it will read. Some languages and older British usage use the long scale, where a billion is a million million, so check which one a document means.
Numbers must be written out in full. A value such as 1e6 is not read, and a comma between thousands must group digits in threes (1,234,567). A comma followed by one or two digits looks like a decimal comma, so the tool asks for a dot instead.