numbers – TAMU Health Editorial Style Guide

In general, spell out one through nine. Use figures (also called numerals) for 10 or above and whenever preceding a percentage, address, time, monetary unit or unit of measure (such as distance, dimensions, weights or speeds) or referring to ages. Do so even if it means items in a list or sequence will be done differently. (They had 10 dogs, six cats and 97 hamsters.) Numerals can also be used in all tabular matter and in statistical and sequential forms (Page 1; magnitude 6 earthquake; Rooms 3 and 4; Chapter 2; line 1 but first line).

Always spell out numbers that begin a sentence, except for years. Also spell out numbers in indefinite, fanciful, and casual uses, or in a proper name. If two numbers appear next to each other, spell out the first one and use a number for the second one (forty-two 5-digit codes).

Use numerals with million or billion except in casual uses: I’d like one million flowers; he gave $1 million to the school.

In large figures: Use a comma for most figures greater than 999. The major exceptions are street addresses, broadcast frequencies (1460 kilohertz), room numbers, serial numbers, telephone numbers and years.