Fact family

A fact family is a set of related addition and subtraction facts, or multiplication and division facts.


addition and subtraction fact family


An addition and subtraction fact family uses two addends and their sum to form basic facts.

Examples: Fact families using different sets of numbers

3, 4, and 7:       8, 0, and 8:
3 + 4 = 7   8 + 0 = 8
4 + 3 = 7   0 + 8 = 8
7 - 4 = 3   8 - 0 = 8
7 - 3 = 4   8 - 8 = 0

multiplication and division fact family


A multiplication and division fact family uses two factors and their product to form basic facts.

Examples: Fact families using different sets of numbers

4, 6, and 24:       5, 0, and 0:
4 × 6 = 24   5 × 0 = 0
6 × 4 = 24   0 × 5 = 0
24 ÷ 6 = 4   0 ÷ 5 = 0
24 ÷ 4 = 6   None (5 ÷ 0 is undefined)

Also called related facts, related sentences.

See also basic facts, related facts.