English Plural - Plurals of Numbers

Plurals of Numbers

The following rules apply to the plurals of numerical terms such as dozen, score, hundred, thousand, million, and similar:

• When modified by a number, the plural is not inflected, that is, has no -s added. Hence one hundred, two million, four score, etc. (The resulting quantitative expressions are treated as numbers, in that they can modify nouns directly: three dozen eggs, although of is used before pronouns or definite noun phrases: three dozen of them/of those eggs.)
• When not modified by a number, the plural takes -s as usual, and the resulting expression is not a number (it requires of if modifying a noun): I have hundreds, dozens of complaints, the thousands of people affected.
• When the modifier is a vaguer expression of number, either pattern may be followed: several hundred (people) or several hundreds (of people).
• When the word has a specific meaning rather than being a simple expression of quantity, it is pluralized as an ordinary noun: Last season he scored eight hundreds . The same applies to other numbers: My phone number consists of three fives and four sixes.
• Note the expressions by the dozen etc. (singular); in threes etc. (plural); eight sevens are fifty-six etc.