AP Numerals

By Lindsey de Stefan

The rules pertaining to numerals in the world of copy editing are both extensive and, in some cases, difficult to remember. We must take into consideration that numerals encompass ages, addresses, percents, dates, lengths, weights, decades, and centuries. However, numerals are also figures, letters, or words that represent a number.
A general rule of numerals is this: the numbers one through nine must always be spelled out. For example, two girls or seven days (AP Stylebook 2004 edition, page 176). However, the numbers 10 and higher are written numerically. For example. 12 years (AP Stylebook 2004 edition, page 176).
Ages do not apply to this general guideline. For example, a 5-year-old girl uses the numeral instead of spelling out the number (AP Stylebook 2004 edition, page 176).
When a number is the first word of a sentence, it is always spelled out. However, if the numeral is a calendar year, it DOES NOT need to be spelled out. An example of this would be 1976 was a very good year (AP Stylebook 2004 edition, page176).
All of these rules are enough to give a person unfamiliar with AP Style a very bad headache. And these are only the guidelines deemed most noteworthy. For a complete list of guidelines, see the numerals entry in your AP Stylebook.