Numbers

Q. This question/answer appeared in the November Q&A:

Q. Which is the proper spelling of a generic age: 30s and 40s or 30’s and 40’s?

A. Chicago’s preferred style is thirties and forties, but if you need to use numerals, we recommend leaving out the apostrophes.

The answer states “we recommend leaving out the apostrophes.” Recommend means to advise, appearing to state that there is a choice, yet in the question, surely the apostrophes are incorrect according to the rule of grammar? Thank you, and by the way, what has happened to the fun quips that used to appear in the Q&A answers?

A. The apostrophes aren’t actually incorrect; they’re commonly used. Oxford Dictionaries specifically allows apostrophes for the plurals of single numerals (e.g., 7’s). But they aren’t Chicago style, and we recommend omitting them in the plurals of numbers written as numerals. As for the fun quips, we are professionals here; we can’t just sit around quipping all the time. (But if you’re desperate, you can find a few here.)