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.