Using Numbers and Numerals
(printable version here)
Special thanks to Hans Westerbeek, Tilburg University, The Netherlands, for alerting us to a needed update and a minor correction.
These general rules may assist writers struggling to be consistent when expressing numbers in writing. The first rule would be to consult a handbook for a specific field of study. There exist subtle differences between the formats for Modern Language Association, American Psychological Association, and Chicago Manual of Style.
Spell out as words:
- Numbers that begin a sentence.
- ex.: Three years ago I moved to Virginia.
- Numbers that can be spelled out in one or two words.
- ex.: ten, twenty, and eighty (a hyphenated number like thirty-six equals one word).
- Numbers that are used as compound adjectives.
Express as numerals:
- Numbers that can not be written in one or two words.
- ex.: 153, 2001, and 8,000,000.
- Numbers representing dates, although the day of month may be written out if the year is not included.
- ex.: July 4, 1776, December Seventh (or December 7).
- Numbers in addresses.
- Numbers expressing exact amounts: percentages, fractions, decimals, statistics, scores, or specific sums of money.
- Numbers representing pages, acts, or scenes in plays and literature.
- ex.: page 10, Act III, but "third scene," "part two" are also correct.
- Numbers expressing time (except when followed by "o'clock").
Exceptions and additional rules:
- It is acceptable to express a decade by spelling it out or writing it as a figure.
- If a passage includes numbers that follow one another, one is spelled and the other is represented with a figure.
- ex.: We used ten 2-gallon cans of red paint on the garage.
- Be consistent! If you begin by expressing your percentages with figures, or spelling out your references to decades, make sure you continue to do the same thing for the rest of the project.
Back to 'Sentence Structure and Mechanics'
Writer's Web | Writing Center | Make
an Appointment | Library