- When apostrophe-s is used to form the plural or possessive of a mathematical expression, the punctuation indicator must be used before the apostrophe. If the apostrophe is omitted in print, it must be omitted in braille.
- 1's and 2's
- How many 10's are there in 50?
- Insert +'s or ='s to make true sentences.
- 1s and 2s
- There are four 4s in 16.
- +s or =s
- When apsotrophe-s or "s" is attached to a mathematical expression, it becomes part of that expression and must be punctuated mathematically.
- 1's, 2's, and 3's.
- 1s, 2s, and 3s.