WSU Editorial Style Guide
Numbers below 10 are spelled out.
- Exception: Percentages, semester hours, and grade point averages.
- 10 percent, 3 semester hours, 3.5 grade point average (unless the number begins a sentence).
- Enrollment increased by 25 percent. Twenty-five percent of the students were over the age of 20.
- Exception: It is sometimes better to use numerals in ads, posters, and websites for ease of reading.
- Treat numbers alike in a sentence if they refer to the same thing: “The class of 150 students was separated into smaller groups of 4 students each.”
Use “more than” rather than “over” with numerals.
- “Enrollment is more than 18,000 students.”
Numbers at beginning of sentences
Always spell out numbers at the beginning of a sentence or reword the sentence to avoid spelling out a large number.
Spell out ordinals in text.
- Not 1st, 2nd, 3rd
When ordinal numbers are needed (as in rankings), do not use superscript letters.
- “The program is ranked 16th in the nation” (not 16th).
Ordinals are never needed with months and days.
- “On May 2, the program began” (not “On May 2nd”).
Numbers of four digits or larger
Use a comma for larger numbers.
Very large, round numbers should be expressed with a figure and word.
Exceptions: Dates (1892), temperatures (-1200 degrees), and test scores
Decimals and fractions
List decimals and fractions in figures.
In some cases, a fraction may be spelled out.
- “The professor covered about two-thirds of the chapter during the class.”
- Note that hyphens are used when spelling out fractions.
Figures plus a.m. or p.m. (lowercase with periods) are used to designate time in both text and schedules.
- “The lecture will begin at 10:00 a.m. with a luncheon to follow at noon.”
- Meeting: 5 p.m.
- Note that “noon” is lowercase and is not used with 12:00.
Plurals of numbers
List plurals by adding an “s.”
Centuries and decades
Spell out centuries and decades where possible.
- fifteenth century
- the sixties
If using figures, they should have an “s” at the end.
Write telephone numbers with a hyphen after the area code.
- Do not use a 1 to precede the area code: 800-335-3518
Numbers between -1 and 1
Use plural, not singular, for fractional numbers less than 1.