Spell out at the beginning of a sentence, unless a calendar year.
Spell out numbers under 10; use figures for any number 10 or greater unless it begins a sentence.
Spell out and hyphenate fractions if the number is less than 10.
- two-thirds, one-half
If the number is 10 or greater, the fraction is a figure also.
- 24 1/2
For ordinals, follow the same rule.
- The ninth problem was hard, but the 10th was much easier.
Use the word “percent” instead of the symbol, unless in a chart or other statistical format.
- Three percent, 100 percent
Spell out grade levels.
Do not use nd, rd, st, th with dates.
- Use: Convocation is on October 2.
- Not: Convocation is on October 2nd.
Use an apostrophe to indicate dropped numbers. Add “s” to show plural.
- class of ‘72
- The ‘90s are known for the “grunge” look.
Use a dollar sign and numbers; do not use a decimal and two zeros.
- Use: $100
- Not: $100.00
Use figures with million or billion.
- Use: The campaign raised $50 million
- Not: The campaign raised $50,000,000
Area codes should always be used in external and internal communications and should be followed by a hyphen. Area codes should not be contained by parentheses. Hyphens should not be replaced by periods.
Lowercase should be used for a.m. and p.m. with periods between letters. When a time falls on the hour, omit the zeros.
- Use: 8 p.m.
- Not: 8:00 p.m.
Use noon and midnight instead of 12 a.m. and 12 p.m.
For time ranges, use an en dash surrounded by one space on either side between numerals.
- Use: 2 – 4 p.m., or 9 a.m. – 2 p.m.
- Not: 2-4 p.m., or 9-2 p.m.
For dates ranges, use an en dash surrounded by one space on either side between items.
- Use: January 2 – February 4, or 11/22/15 – 12/3/15
- Not: January 2-February 4, or 11/22/15-12/3/15