Hyphens, En Dashes, Em Dashes

Q. I work for a travel company and we are trying to figure out the proper way to write “eight-night stay.” I feel the number should be spelled out with a hyphen, while other people feel “8 night” is correct. I’ve been trying to find an answer in the style guide, but no luck. Thanks for the help.

A. Chicago style spells out numbers up to one hundred (CMOS 9.2). See also CMOS 7.85, section 1: number + noun: a hundred-meter race, a 250-page book, a fifty-year project, a three-inch-high statuette, but it’s three inches high. Such compounds are hyphenated before a noun but otherwise open.