Spell out numbers between 1 and 9.
Spell out numbers between 1 and 100.
Compound numbers should be hyphenated.
If two or more related numbers are used in a sentence, one below 10 and one a bigger number, their use should be consistent. They can either be spelled out or written as numerals.
If the numbers refer to two different things, they can be written differently.
Numbers at the beginning of the sentence should also be spelled out with the exception of years.
Simple fractions should be spelled out. A more complex fraction can be represented as a numeral unless it is at the beginning of the sentence.
Numbers should be used for dates, addresses, identification, page numbers, decimals and percentages, large fractional numbers, and expressing monetary amounts.
Numbers should be written as numerals when accompanied by abbreviations such as lb, in, mph, rpm, etc.
When the word o'clock is used, the word expressing time should be spelled out; otherwise, a.m., p.m. should be used with a numeral.
If neither o'clock or a.m./p.m. are used in the sentence, the time should be spelled out.