Rulebase

Fractions — Spelling Out and Mixed Numbers

Numbers

Rulebase Summary

Fractions standing alone (not part of a mixed number) are generally spelled out. Technical fractions, unusually long fractions, and musical time references may be written as figures. Mixed numbers — a whole number combined with a fraction — are spelled out when they begin a sentence. When fractions appear as part of a mixed number in running text, use figures; case fractions are preferred, but a slant (virgule) is acceptable.

Morson's Rule 173 · p.110 Morson's Rule 174 · p.111 Morson's Rule 275 · p.155

Examples

A. About 1/2 of the document was redacted.

A. About half of the document was redacted.

A fraction standing alone is generally spelled out.

A. The pipe measured two and 3/8 inches.

A. The pipe measured 2-3/8 inches.

When a fraction is part of a mixed number, use figures for the entire expression.

Transcript Notes

Generally spell out fractions when they are not part of a mixed number (two-thirds, one-fourth, three-quarters). For technical or long fractions and musical time references, use digits (5/32 of an inch, 3/4 time).

When fractions are part of a mixed number, use figures — case fractions are preferred if the keyboard has them (14 3/4 inches). When a speaker uses 'a half' or 'a quarter' without a whole number, use words.

If the speaker says 'fourths' versus 'quarters,' write the expression with 'quarters' as words to preserve the distinction. Exhibit measurements written as decimals (0.006) may be written as decimals even when spoken as fractions ('six-thousandths').

Style Guide References (3)

Morson's

Rule 173 Page 110

Morson's

Rule 174 Page 111

Morson's

Rule 275 Page 155
See also (3)