What is a fact family?

A fact family is a set of number facts made from the same three numbers. For addition and subtraction, three numbers give two addition facts and two subtraction facts. The same idea works for multiplication and division, showing how the two operations undo each other.

Examples

• 3, 4, 7: 3 + 4 = 7, 4 + 3 = 7, 7 − 3 = 4, 7 − 4 = 3.
• 2, 5, 10: 2 × 5 = 10, 5 × 2 = 10, 10 ÷ 2 = 5, 10 ÷ 5 = 2.
• 6, 6, 12: 6 + 6 = 12 and 12 − 6 = 6.

Quick facts

• Fact families show that addition and subtraction are inverse operations.
• Learning one family gives you four facts for the price of one.