Numbers that can be written as one or two words should be spelled out:
Examples:
- There were seventeen students in class today.
- The professor told us that fifty-six students were to participate in the experiment.
Other numbers, including fractions and decimals, can be represented as numerals:
Examples:
- Over 101 dogs were found abandoned at the residence.
- The book had nearly 1,100 pages of text—far too many to read in one week.
- We expect a 5½ percent wage increase next year.
- The plant grew 0.79 inches during the week.
- If any number begins a sentence, it should be spelled out:
Example:
- Five thousand years ago, the English language would be barely recognizable to us now.
Use numerals when they proceed units of measure:
Examples:
- The experiment measured 16 amperes.
- I filled the flask with 5 milliliters.
- I weighed 200 pounds at the beginning of the competition.
For large numbers, use a sensible combination of numerals and words:
Example:
- Looking 9.8 billion years into the past requires a powerful telescope.
Express related numbers in the same style:
Examples:
- Only 5 of 250 delegates showed up for the convention.
- You can earn from five hundred to five million dollars in this venture.
When referring to page numbers in text, use numerals:
Example:
- I referred to page 75 of my textbook when I needed help.