Three-fifths, twenty-one, thirty-seconds.
Thirty-seven, ninety-nine.
836. Use a hyphen in titles composed of two words or more.
Lieutenant-colonel, alderman-at-large, editor-in-chief.
837. Use a hyphen after the first part of a word divided at the end of a line.
838. Use a hyphen in compound adjectives.
Light-blue, 70-horsepower, six-cylinder, seven-passenger, ill-advised.
839. Use a hyphen after prefixes like co-, re-, anti-, post-, etc., when prefixed to words beginning with the last letter of the prefix; when prefixed to proper nouns or proper adjectives; when the compound might become confused with a word of similar spelling.
Co-operation, anti-Christian, re-creation.