Numbers

Beginning of Sentence

Always spell out a number if it begins a sentence

Centuries

Centuries should be spelled out:

When used as an adjective, a hyphen should be placed in between the ordinal number and "century." Note that if referring to two different centuries in the same adjective phrase, the first century referred to should have a dash following it:

Decades

When referring to decades, use Arabic numerals. Never use an apostrophe.

Dates

Use the format: Month Day, Year.

Do not spell out the number for dates.

Do not write out ordinal numbers

Many Numbers

Where many numbers occur within a paragraph or series of paragraphs, maintain consistency in the immediate context. If according to a rule you must use numerals for one of the numbers in a given category, use them for all in that category.

Page Numbers

Note: see also the page on In-Text Citations for more information on how to cite page numbers from sources.

Do not spell out the number for page numbers.

Use p. or pp. only if you are referring to a page number without the author's name.

When referring to a page number in a sentence, you can use "page" or "pages," but do not capitalize "page."

However, it is preferable that you use parenthetical citations (without the use of p. or pp.) when referring to page numbers if possible.

Page Ranges

  • For ranges starting with a page number of 1 through 100 (or multiples of 100), use all digits of the end-range number: 3–10, 71–72, 96–117, 100–104, 1100–1113

  • For ranges starting with a page number of 101 through 109, 201 through 209, and so on, use only the changed part of the end-range number, and include a zero: 101–08, 1103–04

  • For ranges starting with a page number of 110 through 199, 210 through 299, and so on, use two or more digits of the end-range number, as needed: 321–28. 498–532, 1087–89, 11564–615

  • But if three digits of a four-digit first page number change in the four-digit end-range number, use all four digits of the second number: 1496–1504, 2787–2816

Parts of a Book

Use Arabic numerals for chapters, parts, volumes, sections, etc. (i.e. do not spell them out):

When referring to parts of a book generically, or when referencing multiple parts of a book, do not capitalize:

When referring to a specific part of a book, capitalize it:

Percentages

Do not spell out numbers for percentages, and do not use the percentage sign (%). Use "percent," and not "per cent."

In statistical copy that calls for frequent use of numbers, it is acceptable to use %.

Small vs. Large Numbers

Spell out numbers less than 101 and all large numbers that can be expressed in two words.

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