Occasionally, the text calls for a plural number. For example, this could be referring to a set of years, such as the 1950s, or to cards in a deck, such as the red threes. In these cases, follow the usual rules of pluralizing a word. It is tempting to add an apostrophe, but this is not correct! Apostrophes belong to possessives (such as Amy’s mother) or contractions (such as don’t).
Exercise 7 – pluralizing numbers:
1. Which of the below are correct?
(a) There are four tens in a deck of cards.
(b) The 1830s was an interesting decade.
(c) People in their twenties are joining the workforce.
(d) Multiple sixes were identified among the chosen numbers.
Answer to exercise 7:
1. These are all correct! They all follow the normal pluralizing rules and don’t have unnecessary apostrophes.