Q. Is the example below correct? For the sake of consistency, I want to spell out the thousands (e.g., “470 thousand” instead of “470,000”), but I’ve never seen this done and don’t think it’s right. Is there a way to keep thousands and millions consistent within the same sentence? “We waste 470,000 heads of lettuce, 1.2 million tomatoes, 2.4 million potatoes, 750,000 loaves of bread, 1.2 million apples, 555,000 bananas, 1 million cups of milk, and 450,000 eggs every day.”
A. Consistency isn’t always a realistic goal with numbers. For example, no one would write a sentence like this one: “We counted 5.3 million fish in the year 2 thousand, but somehow I managed to catch only 3.4 tens.” In your example, “470 thousand” would be almost as intelligible as “470,000,” but the usual convention is to reserve a mix of words and numerals for millions and above—a cutoff designed to prevent strings of digits that are longer than their verbal counterparts would be (see CMOS 9.8).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In the sentence “It happened on the twenty-fourth of July,” should the date be spelled out or a numeral? CMOS 9.31 only addresses the treatment of ordinals when the month is not mentioned.
A. We get this question a lot. Let’s start with the conventional formats—July 24, 2020 (typical US style); 24 July 2020 (typical style outside the US); 2020-07-24 (ISO style). Each of these uses a cardinal rather than an ordinal numeral for the day, whether the year is expressed or not (i.e., July 24 or 24 July, not July 24th or 24th July). Outside of these conventional formats, our recommendation would be to spell out ordinals for the day of the week even when the month is mentioned: the twenty-fourth of July; the twenty-fourth (but the Fourth of July or the Fourth for the US holiday; see CMOS 8.89). But keep in mind that this rule applies primarily to formal, long-form prose—so it’s possibly a little too formal for many contexts; if you prefer numerals, or if you need to use them to save space, you have our blessing (the 24th of July, or the 24th). And if you follow Chicago’s alternative system of spelling out only one through nine, an all-numeral approach for days will facilitate consistency (e.g., we’ll be offering tours on the 1st, 2nd, and 24th of July).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. When referring to decimals from zero to one, are they singular or plural? For example, “The road extends for 0.8 mile(s).” A coworker is arguing it is singular since it is not more than one, while I believe it to be plural since we are now talking about multiple pieces of one (eight tenths). If it is singular does the same hold true for similar numbers written as fractions?
A. Decimal quantities are considered to be plural; quantities expressed as fractions are considered to be singular. So write “0.8 miles” but “eight tenths of a mile.” For decimal forms, only the number one is singular: 1 mile. Once you add a decimal, even if it’s a zero, it becomes plural: 1.0 miles. See CMOS 9.19.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Regarding spelling out round numbers over one hundred—how should we handle numbers like 1,500? It’s more round than a number like 1,543, but it’s also less round than a number like one thousand. And if it should be spelled out, which is preferred, “one thousand five hundred” or “fifteen hundred”? Thanks!
A. According to CMOS 9.4,“The whole numbers one through one hundred followed by hundred, thousand, or hundred thousand are usually spelled out.” The spelled-out form “fifteen hundred” qualifies. But the hybrid form “one thousand five hundred” does not. Paragraph 9.4 is intended to encourage spelling out round numbers like three hundred thousand, not awkward forms like “three hundred thousand six hundred”—or, for that matter, something like “thirty-three hundred thousand,” which would be better expressed as “3.3 million” (see CMOS 9.8). So write “fifteen hundred” or “1,500,” depending on context. (For example, if numerals are otherwise rare in your text, opt for the former.)
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In the context of computer bits, would you make an exception to the rule about spelling out numbers under 10 (Chicago’s alternative rule), or would you still spell out “zero” and “one”? For example, “Information is represented in bits as 0s and 1s.” Is that correct?
A. When expressing binary bit strings (or any specific numeric component thereof), it makes sense to use numerals: e.g., 11111100011 (binary for 2019). But when discussing binary numbers as a concept—as in your example—you can refer to zeros and ones as the basis of the system. This has the advantage, among others, of avoiding the plural forms 1s and 0s (which in some fonts will look almost like words).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. What is the CMOS stance regarding the use of numerals for a year at the beginning of the sentence? For example, “1980 was indeed a good year.” I see that AP allows it, but I don’t know if you do.
A. CMOS still recommends spelling out any number at the beginning of a sentence (see CMOS 9.5). If the result is awkward, as it often is with a year, the recommendation is to reword: The year 1980 was indeed a good one. This rule is an editorial nicety: a numeral isn’t as effective as a capital letter at signaling the start of a new sentence. In other words, it’s a rule you can break in all but the most polished, CMOS-approved prose—for example, you can ignore it in casual correspondence or where space is at a premium (or if you follow AP style!).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I am preparing an online archive. Many of the items are audio or video recordings. I’ve fruitlessly searched CMOS for the proper way to indicate the total time of a recording—for example, thirty-five minutes and thirty-three seconds. 35 min. 33 sec.? 35m:33s?
A. There are various accepted stylings. At CMOS 14.264 (“Recorded Readings, Lectures, Audiobooks, and the Like”) one example shows the length of a reel-to-reel tape as 1:12:49, and another shows the length of an audiobook as 13 hr., 6 min. An example at CMOS 9.40 (“ISO Style for Time of Day”) suggests the option of putting a zero in front of a single-digit measure of time: 09:27:08.6 = 27 minutes, 8.6 seconds after 9:00 a.m. Based on all these examples, you could use either 00:35:33 (to clarify that it’s 35 minutes, not 35 hours) or 35 min., 33 sec.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Which of the following is correct or preferred? I’m guessing it’s the first option. I’m working on a very important, time-sensitive document, and everything has to be correct according to CMOS.
She’s number one in my book.
She’s number 1 in my book.
She’s No. 1 in my book.
She’s no. 1 in my book.
A. All of those stylings are widely accepted. The default Chicago style for numbers one through ten is to spell them out, so “number one” works well. In certain contexts (such as referring to a list), you might opt for “number 1,” based on Chicago style for “page 1”, “table 1,” and other such expressions.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Why, in many book titles that include ranges of years, is Chicago style for inclusive numbers not followed? As I understand it, Chicago style is to elide the first two digits of the four-digit second number if they are the same as the first two in the first number of the range. The publisher I work for, like many others, follows that rule in general text. But consider, for instance, the subtitle “Self-Portrait of an Actress, 1920–1956.” Do most readers prefer to see titles with ranges of years styled like this one?
A. You’re correct about Chicago’s style for inclusive dates when a writer chooses to abbreviate them, but CMOS is also fine with spelling them out. In fact, paragraph 9.64 says, “In book titles it is customary but not obligatory to repeat all digits.”
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Can you inform me how you would recommend writing out “10:05 a.m.” if an author is very set on using words rather than numerals?
A. Certainly. You can write “five past ten in the morning,” for instance. There are various ways to write times of day. Please see CMOS 9.37 (“Numerals versus Words for Time of Day”) for more suggestions. Please note that it’s conventional to use numerals for odd times like 10:05, however. Spelling out is usually reserved for the hour, half hour, and quarter hour.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]