Chicago Style Workout 77: Numerals

An assortment of metal number forms for a letterpress

The ABCs of 123

In Chicago’s default style for numbers, whole numbers under 101 are usually spelled out, as in three or ninety-three. Chicago’s alternative rule spells out numbers up to and including nine. But some expressions always call for numerals (July 2, page 9), and in scientific and technical contexts, numerals (also called digits) are the norm.

How well do you know your way around expressions that use numerals? Take the quiz to test your knowledge.

Subscribers to The Chicago Manual of Style Online may click through to the linked sections of the Manual (cited in the answers). (We also offer a 30-day free trial of CMOS Online.)

Note: Style guides sometimes disagree. Except for a few details that can be verified in standard dictionaries and encyclopedias and other readily available sources, the answers in this quiz rely on the information in the 17th edition of CMOS.

Chicago Style Workout 77: Numerals

1. How many years are represented by the range 327–21 BCE?
2. Hank Aaron retired from Major League Baseball with a lifetime batting average of .305.
3. In the twenty-four-hour system, midnight can be expressed as either 00:00 or 24:00.
4. To ensure legibility, CMOS advises using an apostrophe for the plural of a number, whether spelled out or not, as in “two’s and three’s” and “90’s and 100’s.”
5. In Chicago style, all numbers expressed as numerals of four digits or more include a comma.
6. Which is proper Chicago style for a hypothetical ordinal number represented by a letter?
7. Unlike the numbers one (first), two (second), and so on, zero lacks an ordinal form.
8. Which of the following is the style specified by the International Organization for Standardization (or ISO) for the date this quiz was first published?
9. In some regions of the world, the decimal place is marked by a comma.
10. Roman numeral MV̅ (with a line over the V) represents what number?


Metal numbers by adimas / Adobe Stock.

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