GCF and LCM of 5 and 8
The greatest common factor and least common multiple of 5 and 8.
GCF of 5 and 8
1
LCM of 5 and 8
40
How it works
Break each number into its prime factors:
- 5 = 5
- 8 = 2³
The GCF (1) multiplies the primes both share, at the lowest power each appears. The LCM (40) multiplies every prime that appears in either number, at the highest power — which is also 5 × 8 ÷ 1 = 40.
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Frequently asked questions
What is the GCF of 5 and 8?+
The greatest common factor (GCF) of 5 and 8 is 1 — the largest number that divides both 5 and 8 with no remainder.
What is the LCM of 5 and 8?+
The least common multiple (LCM) of 5 and 8 is 40 — the smallest number that both 5 and 8 divide into. It equals 5 × 8 ÷ GCF = 40 ÷ 1 = 40.