Spell out zero through nine if the number does not precede a unit of measure or is not used as input. Use numerals for 10 and higher.
NOTE: The exception to this is if the number, higher than nine, begins a sentence. Then, the word must be written out.
When two numbers that refer to separate categories must appear together, spell out one of them.
EXAMPLE:One booklet has 16 pages, one has 7 pages, and there are ten 12-page booklets.
Use numerals for all measurements, even if the number is under 10. This is true whether the measurement is spelled out, abbreviated, or replaced by a symbol. Measurements include distance, temperature, volume, size, weight, points, and so on, but generally not days, weeks, or other units of time. Bits and bytes are also considered units of measure.
Use numerals to indicate the time of day.
Hyphenate compound numbers when they are spelled out.
EXAMPLE:Twenty-five fonts are included.
Spell out fractions whenever possible.
Spell out ordinal numbers.
Do not use ordinal numbers for dates.
Do not use -ly (firstly, secondly).
Spell out reference to age, like She's in her thirties.