Q. Are digits (e.g., 4, 8) appropriate for use in illustrations or diagrams to save space, even if they would be spelled out in text (e.g., four, eight)?

Q. In the following conversion in prose, should it be written “six feet (1.80 meters)” or “six feet (1.8 meters)”?

Q. Is there a correct way to write a range of only two numbers in a complete sentence? For example, June 3–4, or June 3 and 4? Pages 75–76, or pages 75 and 76? The issue gets especially ugly when referring to multiple numbers. For example, “The event will take place Nov. 3 and 4, 8 and 9, 15 and 16, and 21 and 22.” Yuck. I say that for ease of reading, an en dash would be used. However, I know that according to CMOS, an en dash between two numbers implies “up to and including,” or “through.” With that in mind, should “and” be used, because no number comes between the two numbers that are cited? Or is that overthinking things?

Q. My coworkers and I are debating what exactly is meant by the word isolated in CMOS 9.20 (“isolated references to amounts of money are spelled out for whole numbers of one hundred or less”). One opinion is that two or more references to amounts of money in one sentence no longer qualify as isolated, as in “He had $0.21 and she had $21.00.” The other opinion is that one sentence containing two or more references to amounts of money could still qualify as isolated if the surrounding text does not mention money, as in “He had twenty-one cents and she had twenty-one dollars” in a passage contrasting the two people personally with no other reference to money. Could you please settle our debate?

Q. I am writing a fictional piece that includes a discussion of the Fujita scale of tornado intensities. I am trying to write “318 miles an hour, the top wind speed of an F5 tornado.” I know the Manual wants most numbers spelled out up through 999, but writing “three-hundred-eighteen miles an hour” just doesn’t look right.

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?

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

Q. Which is correct: 12,000,000 or 12 million?

Q. At work I was questioned about the use of numerals versus words in the following sentence: “Table 7 reports the number of cases in which individual debtors filed for protection under Chapter 13 and stated on Official Form 1 that they had filed a case during the preceding eight years.” I had previously explained to this person that if you use numerals for a number greater than 10 in one part of a sentence, you should also use numerals for other similar numbers in that sentence that normally would be spelled out. When she read the sentence cited above, she asked why the second-to-last word (eight) wasn’t replaced with a numeral (8), given that I had used numerals earlier in that sentence. I explained that the other numerals were part of the title of a table, bankruptcy law chapter, and form, so they weren’t in the same category as the last number and thus did not require me to write “8 years.” Am I correct?

Q. When working with technical material, what symbol should I use between dimensions? For instance, in CMOS 3.27, the following example has a symbol that doesn’t seem to match either a multiplication symbol or a lowercase x, and the symbol is elevated above the baseline: “Oil on canvas, 45 × 38 cm.” What is that symbol called, and where is it discussed in the Manual?