Factor pairs
Factor pairs multiply back to the original number. They are useful for factoring expressions, simplifying fractions and checking divisibility.
Example
For 84, factor pairs include 1 x 84, 2 x 42, 3 x 28, 4 x 21, 6 x 14 and 7 x 12.
How the method works
You only need to test divisors up to the square root of the number. Each successful divisor creates a matching factor pair.
Common mistakes
Do not confuse factors with multiples. Factors divide into the number; multiples are produced by multiplying the number.
Last reviewed: 2026-05-17