Whether to Express Numbers As Words or Numerals
Numbers are so precise, so predictable, we can hit the moon with a rocket in any language (as long as we remember to convert inches to millimeters); but English Language authorities cannot agree on how to write those numbers. The Chicago Manual of Style disagrees with the MLA Handbook, which contradicts the Publication Manual of the American Psychological Association, which never considers what college professors teach journalism students. The Chicago Manual of Style notes, “As soon as one thinks one has arrived at a simple rule for handling some category of numbers, exceptions begin to appear, and one realizes that the rule has to be made more complicated.” But we can follow a few conventions to bring sanity to our writing lives.
The Central Question: Should we spell a number or use the numeral? There are two answers, of course, one contradicting the other: Many texts suggest we spell only numbers from one through nine (and their multiples): so three and seven thousand, but 23; others suggest spelling numbers from one through ninety-nine (and their multiples): so fifty-six and thirty-nine million, but 102 and 5,329. I prefer the second method, but either is fine; just be consistent.
With that as our foundation, here are thirteen (or 13) exceptions; there are more, but unless you are a publisher, these will suffice. Note that most of the time, we use the numeral:
Use Numerals with:
Number Combinations: When you compare numbers, be consistent; if some should be words and others should be numerals, make them all numerals: In one year, Criss Angel walked through 108 concrete walls, 73 plate glass windows, and 2 iron gates.
Large Rounded Numbers: about 8 billion.
A Year: 47 B.C. (or B.C.E.).
Number Clusters: The ages of the six conscripts were 7, 9, 10, 12, 13, and 15.
Percentages and Decimals: 5 percent, .62 miles.
Units of Measurement in technical writing: 3 pounds, 17 hectares.
Abbreviated Measurements in all writing: 5 mi, 55 mph.
Whole Numbers with Fractions: 8½-by-11-inch paper.
Page Numbers: page 4.
Use Words with:
Units of Measurement in nontechnical writing: The last time David Blaine stabbed himself, he lost three pints of blood.
Round Numbers and Approximations: about two thousand years ago.
Use Both with:
Numbers Modifying Numbers: 4 sevens, or three 10s.
“Ordinal” Numbers (numbers that express order): same rules as for “cardinal” numbers: first, second, twenty-third (or 23rd), but 137th.
Back on the street. After I cut the deck thirteen (or 13) times, I distracted you by talking about numbers, while I dealt thirteen hands. Now, I flip over each hand, and voilà, I have four-of-a-kind every time! Amazing! How does he do that? Ask David and Criss, and they will tell you: Nothing up our sleeves but numbers. See you in the streets again next week for more on numbers. In the meantime, you can try the WordRake editing software, free for seven days.