Q. Which is the most correct phone number formatting—(xxx) xxx-xxxx, xxx-xxx-xxxx, or xxx.xxx.xxxx? Which is the most accessible?

A. You’ve punctuated your hypothetical telephone numbers—which are in the form most often used in the United States and Canada—in order of most familiar, most straightforward, and least conventional.

Putting the area code in parentheses is supposed to suggest that dialing it is optional. As area codes have increasingly become necessary even for local calls, this convention has nonetheless remained common.

As for accessibility, in our brief tests (using numerals rather than *x*’s), all three formats were read as phone numbers by both Microsoft Word’s Read Aloud feature and Microsoft’s Narrator—that is, as a series of ten individual digits with a pause after the third and sixth and not as three large numbers, two of them in the hundreds and one of them in the thousands. And each was automatically turned into a callable phone number link in various messaging and email apps on a smartphone.

But only the first two are mentioned in the recommendations published by the International Telecommunication Union, so we’d advise using one of those (the ones without periods). See also *CMOS* 9.57.

Q. I’m finishing a book manuscript that includes uncommon fractions (such as 1/72) for which there aren’t single Unicode characters. How should I render my fractions? Using superscript for the numerator and subscript for the denominator results in inconsistent spacing. Even the existing Unicode fractions aren’t consistently kerned. Is there a way to have uniform-looking fractions regardless of the specific numbers? Thanks for your help.

A. You’re right that a single-character Unicode fraction like ½ (U+00BD, vulgar fraction one half) won’t match a fraction like 1/72 that relies on the forward slash (or solidus) character. One approach that can work in HTML (which is what you’re viewing right now) is to use a fraction slash (U+2044) instead of an ordinary forward slash (U+002F, the character that shares a key with the question mark on English-language QWERTY keyboards).

Unlike the forward slash, the fraction slash is designed to kern tightly to any character immediately before or after it. Best of all, the numbers before and after the slash will automatically go into fraction mode, adjusting their size and position relative to the slash (though not in all fonts):

*Fraction slash, no superscripts or subscripts:*

1⁄2 and 2⁄3 and 3⁄4 and 5⁄8 and 3⁄16 and 1⁄72

*Forward slash (solidus), with superscripts and subscripts:*

^{1}/_{2} and ^{2}/_{3} and ^{3}/_{4} and ^{5}/_{8} and ^{3}/_{16} and ^{1}/_{72}

Both versions have a certain consistency to them, but the first set of fractions is better at matching the look of Unicode’s vulgar fractions. And according to the applicable Unicode chart (in what Unicode defines in its Help pages as an “informative note”), the fraction slash is intended “for composing arbitrary fractions”—which is the goal in this case.

But this approach won’t automatically work across applications. In a book manuscript composed in Word, you should probably use ordinary numbers with the forward slash—as in “1/72”—and ask your publisher or typesetter to format the fractions for you (e.g., using the available tools in a program like InDesign), specifying that you want them all to look like Unicode’s ½.

Q. Would you spell out 150,000?

A. Use numerals for 150,000. The applicable principles are as follows:

- Spell out numbers one through one hundred (Chicago’s general rule).
- Spell out multiples of one through one hundred used in combination with
*hundred*, *thousand*, or *hundred thousand*.

So you would spell out “five thousand” and “one hundred thousand” but use digits for 150,000—because 150 would normally be rendered as a numeral.

But if you’re following Chicago’s alternative rule of using digits for 10 and up, all such larger numbers are usually given as numerals. Rather than, for example, “fifteen thousand” or “15 thousand,” you’d write 15,000.

For more details, see *CMOS* 9.2, 9.3, and 9.4. For numbers with *million*, *billion*, and so forth, see *CMOS* 9.8.

Q. I am editing an article that has sports terminology in it, and I wanted to verify whether a player’s jersey number would fall under the general rule of numbers or would be a special case in which the jersey number would be written as a numeral. And if it is to be written as a numeral, would an octothorpe/hashtag be used (for example, #24)?

A. Jersey numbers (like page numbers and a few other categories) are best expressed as numerals to reflect the way they normally appear in real life: *Upon his much-anticipated return to the court, he wore number 45.** Usually, the word “number” can be spelled out; if you need to abbreviate it, we’d recommend using “No.”† instead of the number sign‡ (i.e., No. 45).

* Hint: The year was 1995, when *CMOS* was in its fourteenth edition.

† For the capital *N*, see this Q&A on a related matter (the No. 2 pencil).

‡ “Number sign” is Unicode’s name for # (U+0023); the code chart for that symbol also lists *pound sign*, *hashtag*, *hash*, *crosshatch*, and *octothorpe* as what it calls informative aliases (which are preceded by equals signs in the charts; see “Key to the Unicode Code Charts” at Unicode’s Help and Links page).

Q. Sorry if I’ve overlooked a *CMOS* (or Q&A) answer to this question. I’m reviewing an organization’s bylaws, which contain several instances of a number spelled out followed by the number as a numeral in parentheses: e.g., “two (2).” I think parenthetical numerals are pointless redundancies. Does *CMOS* have a rule or preference related to this?

A. *CMOS* doesn’t cover this, but we agree with you, as does legal scholar and grammarian Bryan Garner: “The repetition of numbers by spelling them out and then using numerals typifies legalese and should never be used outside legal drafting. . . . Even in modern legal documents it’s largely uncalled for—the convention harks back to the days of legal scribes, who doubled words and numerals to prevent fraudulent alterations (words controlled over numerals).” See *Garner’s Modern English Usage* (Oxford, 2022), under “Numerals (G).”

Garner’s parenthetical observation that “words controlled over numerals” is interesting. In “two (3),” for example, the mistake would almost certainly be with the 3 and not the *two* (it’s easy to press a 1 or a 3 when a 2 is intended). That parenthetical numeral is subject not only to “fraudulent alterations” but to typos.

Q. When referring to the number of points possible on an exam, should I style numbers according to *CMOS*’s general rule, or should I use numerals even for numbers below 101? Using numerals seems more common, but I’d like to know whether *CMOS* has an opinion.

A. There are many categories where numerals are generally used instead of words, from page numbers to sports scores. Whenever you suspect numerals would be more appropriate in a given scenario, particularly when referring to a type of number that would normally be expressed as a numeral in the wild (as page numbers on the pages of a book, scores on a scoreboard—or points tallied on an exam), then use numerals, even for numbers under 101.

Q. Hi. How do you write out grade levels? For example, would it be “third grade” or “3rd grade”? “Grade three” or “grade 3”? I cannot find the answer in *CMOS* 17; did I miss it? Thanks in advance!

A. Write “third grade” and “grade 3.” In Chicago style, the numbers zero through one hundred (*CMOS* 9.2) or, alternatively, zero through nine (9.3) are spelled out. This applies whether the number is a cardinal (“one”) or an ordinal (“first”). But numerals are preferred in many expressions where the number follows the noun. For example, we’d refer to page 3, act 7, room 9, and Highway 2. Examples like these appear throughout *CMOS*, but none with grade levels. We’ll try to add some in a future edition.

Q. I understand a space is necessary between a number and a fraction when the fraction symbol is unavailable (e.g., 2 1/2), because the number would be illegible without it. But what if you use the symbol?

A. Fractional quantities expressed as a numeral plus a symbol are normally written without a space, as in 2½ or 5⅞. See *CMOS* 9.15 for examples.

Whether the symbol is used or not, these are known as “vulgar” fractions. For example, the Unicode name for “⅞” is “vulgar fraction seven eighths.” In this context, “vulgar” means “common.” We can only guess, then, that decimal fractions (e.g., 0.875) would be considered fancy by comparison.

Q. I’m editing a book that follows Chicago’s general rule for spelling out numbers zero through one hundred. In the construction “on a scale of 1 to 10,” would you spell out the numbers or use numerals? Thanks!

A. According to Google’s Ngram Viewer, numerals have been consistently more common in that expression in published books—but only slightly.

Would “1 to 10” be even more popular if *CMOS* 9.2 didn’t advise spelling out numbers one through one hundred in most contexts? Maybe.

But you can take this answer as permission to use numerals, which seem to do a better job than spelled-out numbers at suggesting the hypothetical scale in that expression.

Q. I am writing about pencils. The piece has to conform to *CMOS*. How am I supposed to write “No. 2 pencil,” which isn’t a proper name, but nearly so? If I write “Number 2,” it doesn’t seem to be “better.” Thoughts?

A. Where *CMOS* fails to offer a specific ruling, follow common usage. This often means looking to Merriam-Webster, but since there’s no entry there, you’ll have to do some digging.

Pencil companies seem to prefer the form “No. 2” (as on this page from Dixon Ticonderoga), though “#2” is also common. According to Google’s Ngram Viewer, those forms also happen to be at or near the top of the list of how such pencils have been referred to in books published since 1900. Book editors often default to spelling out abbreviations and numerals in running text, but even so, most of the spelled-out forms trail the abbreviations:

And though “number 2 pencil” would be okay with us—in line with “type 2 diabetes,” “size 10 dress,” and “type A executive” (see *CMOS* 7.89, sec. 2, under “noun + numeral or enumerator”)—we’d argue from the evidence above that “No. 2” will be more familiar to readers.

A third option—spelling out the whole thing (“number two”)—would be okay also (it’s the second most common usage). But as with dress sizes (and page numbers), a numeral matches what’s usually on the item itself.

As for the capital *N* in “No.,” there’s a close analogy in “No. 1”—as in “we’re No. 1.” That’s how “number one” in that sense is “often written” according to Merriam-Webster. It’s maybe not surprising, then, that the form “no. 2 pencil” (lowercase *n*) doesn’t even chart in an ngram (unless its absence stems from a limitation in Google’s data).

As most editors who work on paper would know, the “2” refers to hardness. A No. 2 pencil leaves less graphite on the paper than the softer No. 1 (which makes darker marks), but more than the harder No. 3 (which makes lighter marks). According to a more common classification system, a No. 2 pencil is an HB. *H* refers to hardness, *B* to blackness. So whereas an H pencil would be hard (and light), a B would be soft (and dark); HB is in the middle. These grades can also include numbers. For example, an 8B is softer than a 6B.

For more information on these and other details, see *The Pencil: A History of Design and Circumstance*, by Henry Petroski (Knopf, 1990).