Hyphenation of numbers is governed by established stylistic conventions, primarily when writing out numbers as words. This practice most commonly applies to compound numbers from twenty-one through ninety-nine (e.g., forty-two, eighty-seven) and written-out fractions used as adjectives (e.g., a two-thirds majority, a one-half share). However, a fraction used as a noun is typically not hyphenated (e.g., One half of the population agreed).
Consistent application of these hyphenation rules improves readability and clarity in written communication. It minimizes ambiguity, especially in complex sentences where multiple numerical values are present. Historically, these conventions evolved to standardize written expression and ensure uniformity across various publications and professional documents.
