Words or numerals? - General rule - Numbers - Part III. Style 20 spelling

A manual for writers of research papers, theses, and dissertations, 7th edition - Kate L. Turabian 2007

Words or numerals? - General rule
Numbers
Part III. Style 20 spelling

This chapter offers general guidelines for presenting numbers. These guidelines are appropriate for most humanities and social science disciplines, but disciplines that rely heavily on numerical data may have more specific guidelines. If you are writing a paper in the natural or physical sciences, mathematics, or any other very technical field, follow the conventions of the discipline. For style guides in various disciplines, see the bibliography.

In some cases, you may need to adapt these guidelines to situations not described here. If so, be consistent.

If you are writing a thesis or a dissertation, your department or university may have specific requirements for presenting numbers, which are usually available from the office of theses and dissertations. If you are writing a class paper, your instructor may also ask you to follow certain principles for presenting numbers. Review these requirements before you prepare your paper. They take precedence over the guidelines suggested here.

23.1 Words or numerals?

The most common question in presenting numbers is whether to spell them out in words (twenty-two) or give them in numerals (22). When the number is followed by a unit of measure, you must also decide whether to give that unit in words (percent) or as a symbol (%) or an abbreviation.

The guidelines presented in 23.1—23.3 pertain to numbers used in the text of your paper. For numbers used in tables, figures, and citations and in the structure of your paper, see 23.4.

Unless otherwise specified, numerals here means arabic numerals (1, 2, 3, etc.). For roman numerals (i, ii, iii, etc.), see table 23.1.

23.1.1 General rule

Before you draft your paper, you should decide on a general rule for presenting numbers and follow it consistently. Which rule you choose depends on how many numerical data you are presenting and the conventions of your discipline. For situations in which you might modify this rule, see 23.1.2—23.1.8.

In the humanities and social sciences, if you use only a few numerical data, spell out numbers from one through one hundred. If the number has two words, use a hyphen (fifty-five). Also spell out round numbers followed by hundred, thousand, hundred thousand, million, and so on. For all other numbers, use arabic numerals. Follow this pattern for numbers that are part of physical quantities (distances, lengths, temperatures, and so on), and do not use abbreviations for the units in such quantities (see 24.5).

After seven years of war came sixty-four years of peace.

The population of the three states was approximately twelve million.

He catalogued more than 527 works of art.

Within fifteen minutes the temperature dropped twenty degrees.

If your topic relies heavily on numerical data, follow a different rule: spell out only single-digit numbers and use numerals for all others.

This study of 14 electoral districts over seven years included 142 participants.

He hit the wall at 65 miles per hour, leaving skid marks for nine feet.

In the sciences, your general rule may be to use numerals for all numbers, except when they begin a sentence (see 23.1.2). You may also use abbreviations for quantities (see 24.5).

The mean weight proved to be 7 g, far less than predicted.

With any of these rules, use the same principles for ordinal numbers (first, second, etc.) that you use for standard ones. Add st, nd, rd, or th as appropriate.

On the 122nd and 123rd days of his trip, he received his eighteenth and nineteenth letters from home.