Numerals or Words?

When should you spell numbers and when should you use numerals?  The answer depends on the style guide that you use.

The Chicago Manual of Style calls for numbers between one and one hundred to be spelled:

In nontechnical contexts, the following are spelled out: whole numbers from one through one hundred, round numbers, and any number beginning a sentence.  For other numbers, numerals are used. (9.3)

The MLA Handbook states that in pieces of writing that infrequently use numbers (i.e. the Humanities), numbers that are either one or two words should be spelled and numbers of three or more words should be in numerals:

One, thirty-six, ninety-nine, one hundred, fifteen hundred, two thousand, three million, but 2½, 101, 137, 1,275. (3.5.2)

In more scientifically based papers, MLA requires writers to represent any number followed by a technical unit of measurement as a numeral: “16 amperes, 5 millimeters” (3.5.2).

The general rule for APA is to use words for numbers zero to ten, but numerals for numbers ten or greater: 11, 200, 5000 (4.30).

Works Cited

The Chicago Manual of Style. 15^th ed. Chicago: U of Chicago P, 2003.

MLA Handbook for Writers of Research Papers. 7^th ed.  New York: MLA, 2009.

Publication Manual of the American Psychological Association. 6^th ed.  Washington, DC: American Psychological Association, 2009.