Let’s Talk About Hyphens, Again Leave a Comment / By How do you hyphenate numbers?Is it a 250-page book? Or a 250 page book?Is it twenty-eight? Or twenty eight? Number + NounAny number that precedes a noun is hyphenated.Hence, A 250-page book is correct.But, watch out for five- to ten-minute intervals. It has a space after the first hyphen. Numbers, Spelled OutTwenty-one through ninety-nine are hyphenated; numbers above one hundred are open (no hyphens). e.g. five hundred fiftyThat means twenty-eight is the correct answer. Add Me to The Question of the Week Mailing List