Presenting numbers in running text can be confusing to people who want their documents to be formatted correctly. We're asked to copyedit number-rich documents often, and offer this advice, taken from the Chicago Manual of Style:
Numbers applicable to the same category should be treated alike within the same context, whether a paragraph or a series of paragraphs; do not use numerals for some and spell out others. If according to the rules you must use numerals for one of the numbers in a given category, then for consistency's sake use numerals for them all:
- There are 25 waterskiers on the south lake, 56 on the north lake, and 117 on the river, making a total of 198 waterskiers at camp today.
- In the past ten years fifteen new buildings have been erected. In one block a 103-story office building rises between two old apartment houses only 3 and 4 stories high.
- The population of Harrison, Maine, grew from 10,000 to 175,000 in only thirty years.
Note that, as in the foregoing examples, numbers in the same context but representing different categories may be treated differently.
First Word in Sentence
At the beginning of a sentence any number that would ordinarily be set in numerals should be spelled out instead, regardless of any inconsistency this may create:
- One hundred ten loaves and 103 fish were left over after the meal.
- Thirty-eight percent of the people paid attention.
- Nineteen fifty-three was a good year for Virginia.
- Thirty-three thousand people were courtside to watch Andy Roddick win the U.S. Open on Sunday.
If spelling out a number that begins a sentence is impracticable or cumbersome, the sentence should be recast so that it does not begin with a number:
- Virginia saw a very good year in 1953.
- The year 1953 was a very good one for Virginia.