Q. What is the correct way to report ages of people? In what cases, if any, would it be acceptable to use numerals? Our company’s
style guide follows CMOS, but suggests using figures in reporting ages. I appreciate your guidance.
A. It’s usual to use numerals in lists, in tables, and in any context where an abundance of numbers makes
spelling them out awkward.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hi, CMOS people, I can’t quite seem to figure out whether I should use spelled-out numbers or numerals with units of time—for example, seconds, minutes, hours, days, months, years. I am not sure whether it should be “2 to 4 weeks” or “two to four weeks”; “30 years” or “thirty years”; etc. I think for numbers over 99, numerals are used, for example “230 seconds.” I understand that numerals should be used with units of measure in general, like kg, cm, °C, and °F, etc. Thank you for your help.
A. For units of time (or any other measure) in nontechnical text, we like to spell out numbers up to and including one hundred: “The cake burned in forty-one minutes.” If, however, in a given paragraph the same time unit involves a mixture of numbers under and over one hundred, we style them all the same: “Ten runners clocked in at 94 minutes, and forty-three more finished in 101 minutes.” (Note that the numbers of runners are not changed to numerals because in that category there is no inconsistency in styling them according to the rule.)
Numerals are always used with abbreviated measures like the ones you list; and in technical or statistical texts, numerals are used even when measures are spelled out. Sometimes even nontechnical text will have a passage containing many numerical references, in which case the editor might decide to use numerals for all in order to save space and prevent what might seem to be inconsistencies. See chapter 9 in CMOS for a detailed discussion.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hi. Is it acceptable to begin a sentence with a mathematical variable? I had been going by the thinking that since one spells out a number when beginning a sentence, one would not begin a sentence with a variable or other mathematical expression. However, I have seen numerous such occurrences in journal articles, leading me to think that copy editors would have made corrections if this were considered a stylistic error. I have not been able to find any advice about this, and so I was wondering about your stance on it. Thank you.
A. In general, a variable or other mathematical symbol should not begin a sentence. For examples and suggested remedies, see CMOS 12.7.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. A colleague writes: “Basement space is about 5,700 square feet, but about 12,000 square feet is available
on the eighth floor.” I suspect the point is arguable, but couldn’t that be “12,000
square feet are available on the eighth floor”?
A. Although it might seem counterintuitive, quantities of weight or measure are considered singular: five dollars is enough;
three cups of flour makes one loaf. When you think about it, “12,000 square feet are available”
reads as though someone short of cash could buy just one or two of them.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. If I’m expressing a range of percentages in a statistics-heavy paragraph of academic social sciences prose, does the percent sign commute? For example, does “50 to 55% of respondents” make sense, or should I use a percent sign after each numeral, making it “50% to 55%” instead? What about other units of measurement? Is “from 100 to 110km” better or worse than “from 100km to 110km”?
A. Please see CMOS 9.17: “For expressions including two or more quantities, the abbreviation or symbol is repeated if it is closed up to the number but not if it is separated: 35%–50%, but 2 × 5 cm.” (See 10.49 and 10.58 for when to use a space before a symbol.)
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I see the word “that” in constructions where clarity would not be diminished
without it. An example in the Q&A was “He thinks that, if he asks for directions, his membership in
the brotherhood of men will be revoked.” I consider “He thinks if he . . .”
correct.
A. Both constructions are correct, but leaving out “that” can lead to confusion
whenever the next noun can be mistaken for an object of the verb (I judged for thirty years the county fair pickling contest
was rigged). It’s safer to include “that.” You can always
reconsider if it is awkward for any reason.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In a large document, I am spelling out numbers under 100. For consistency, if I have a sentence with a list that includes 99 and 101, I would write them both as numerals. Does this rule apply per sentence, per paragraph, per page, per report? This feels like such a silly question, but I honestly am struggling with it.
A. CMOS 9.7 calls for consistency “in the immediate context,” which you might call “within eyeshot”—that is, anywhere you think a reader might be distracted by the inconsistency.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In expressing the statistical change in GDP figures over the course of multiple decades, would it be most correct to write
“2000% increase,” “2,000% increase,”
or “2,000 percent increase”? Our copyeditor favors the second option, but the
use of the comma in that context just doesn’t sit right with me. Please advise.
A. All those styles are acceptable. In text, Chicago style spells out “percent”
and favors a comma in integers over 999, but if your numbers appear in a table, “2000%”
might look better.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I have been under the impression that extensions on a date (st, nd , rd, etc.) are proper when used simply with a month (January 15th) but are not used in connection with a year (January 15, 2009).
Please advise if this is correct or provide instruction to the contrary.
A. Chicago style doesn't include the extensions in either case. When the ordinal is called for, we spell it out: the fifth of
the month. That said, the style that you describe is common and not incorrect.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. This has to do with page ranges for a bibliography, as described in CMOS. It is clear that 125–29 is correct and 125–129 is not. However, it is not clear
what to do with a range like 145–155. Should it be 145–55 or 145–155?
The trouble comes from the part of the explanation that reads “use two or more digits as needed”
and the lack of examples to address this particular situation. I would think 145–55 is sufficient, but
then, I don’t trust my own intuition because 125–9 seems sufficient to me, too.
And that is wrong. Please help!
A. Using “two or more digits as needed,” a rule of thumb for certain inclusive numbers,
means using more than one digit but no more digits than you need: 145–155 uses more digits than you
need, and 125–9 uses only one digit, so 145–55 and 125–29
are Chicago’s preferred style. However, 145–155 (using all digits) and 125–9
(using only the digits that change) are also perfectly good styles; CMOS includes them as alternatives.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]