Plurals and punctuation - Numbers - Style

A manual for writers of research papers, theses, and dissertations, Ninth edition - Kate L. Turabian 2018

Plurals and punctuation
Numbers
Style

23.2.1 Plurals

Form the plurals of spelled-out numbers like the plurals of other nouns (see 20.1).

Half the men surveyed were in their thirties or forties.

Form the plurals of numbers expressed in numerals by adding s alone (not ’s).

The pattern changed in the late 1990s as more taxpayers submitted 1040s online.

To fly 767s, the pilots required special training.

23.2.2 Commas within Numbers

In most numbers of four or more digits, set off thousands, hundreds of thousands, millions, and so on with commas. (In the sciences, commas are often omitted from four-digit numbers.)

✵ 1,500

✵ 12,275,500

✵ 1,475,525,000

Do not use a comma within a four-digit year; do use one for a year with five or more digits (see also 23.3).

✵ 2007

✵ 10,000 BC

Do not use a comma in page numbers, street addresses, telephone or fax numbers, zip codes, decimal fractions of less than one, or numbers included in organization names.

✵ page 1012

✵ 0.1911 centimeters

✵ 15000 Elm Street

✵ Committee of 1000

23.2.3 Other Punctuation within Numbers

Numbers sometimes include internal punctuation other than commas. For periods (decimals), see 23.1.3 and 23.1.4; for colons, see 23.1.5; for hyphens, see 23.1.1 and 23.1.3; for dashes, see 23.2.4.

23.2.4 Inclusive Numbers

To express a range of numbers, such as pages or years, give the first and last (or inclusive) numbers of the sequence. If the numbers are spelled out, express the range with the words from and to; if they are expressed in numerals, use either these words or a connecting hyphen with no space on either side. In some settings, such as citations, always use hyphens (see chapters 16—19). Do not combine words and hyphens in expressing inclusive numbers.

✵ from 45 to 50

but not

✵ from 45—50

✵ 45—50

but not

✵ forty-five—fifty

For inclusive numbers of one hundred or greater, you may either use full numbers on either side of a hyphen (245—280 or 1929—1994) or abbreviate the second number. Table 23.2 shows one system of abbreviation.

This system works well for page numbers, which never include commas (see 23.2.2). For numbers that include commas, use the system shown in table 23.2, but repeat all digits if the change extends to the thousands place or beyond. Never abbreviate roman numerals (see table 23.1).

✵ 6,000—6,018

✵ 12,473—79

✵ 128,333—129,114

✵ xxv—xxviii

Table 23.2. Abbreviation system for inclusive numbers

First number

Second number

Examples

1—99

Use all digits

3—10, 71—72, 96—117

100 or multiples of 100

Use all digits

100—104, 1100—1113

101 through 109, 201 through 209, etc.

Use changed part only

101—8, 808—33, 1103—4

110 through 199, 210 through 299, etc.

Use two digits unless more are needed to include all changed parts

321—28, 498—532, 1087—89, 1496—500, 11564—615, 12991—3001

For years, give all digits for a span that includes more than one century. Also give full dates in a system in which dates are counted backward from a specific point (most notably BC, “before Christ,” and BCE, “before the common era”). Otherwise use the system shown in table 23.2. See 23.3 for more on date systems.

✵ the years 1933—36

✵ the winter of 1999—2000

✵ 15,000—14,000 BCE

✵ 115 BC—AD 10