Numbers and Percentages
19.1 Use of Numerals
19.1.1 Numbers of 4 or More Digits to Either Side of the Decimal Point
19.1.2 Mixed Fractions
19.1.3 Measures of Time
19.1.4 Measures of Temperature
19.1.5 Measures of Currency
19.2 Spelling Out Numbers
19.2.1 Beginning a Sentence, Title, Subtitle, or Heading
19.2.2 Common Fractions
19.2.3 One Used as a Pronoun
19.2.4 Accepted Usage
19.2.5 Ordinals
19.3 Combining Numerals and Words
19.3.1 Rounded Large Numbers
19.3.2 Consecutive Numerical Expressions
19.4 Use of Digit Spans and Hyphens
19.5 Enumerations
19.6 Abbreviating Number
19.7 Forms of Numbers
19.7.1 Decimals
19.7.2 Percentages
19.7.3 Reporting Proportions and Percentages
19.7.4 Reporting Rates and Ratios
19.7.5 Roman Numerals
Any policy on the use of numbers in text must take into account the reader’s impression that numbers written as numerals (symbols) appear to emphasize quantity more strongly than numbers spelled out as words. Because numerals convey quantity more efficiently than spelled-out numbers, they are generally preferable in technical writing. In literary writing, by contrast, spelled-out numbers may be more compatible with style. Despite these general principles, usage may appear inconsistent when a publication chooses to use numerals in some instances and words in others. The guidelines outlined in this section attempt to reduce these inconsistencies and avoid use of numerals that may be jarring to the reader. In situations that are not governed by these guidelines, common sense and editorial judgment should prevail.