GCF (HCF) of 9 and 12

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Greatest Common Factor of
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What is the Greatest Common Divisor of 9 and 12?

Answer

GCF (HCF) of 9 and 12 is
3

Common factors: 1, 3

3 divides both: 9 ÷ 3 = 3, 12 ÷ 3 = 4 — and 3 and 4 share no factor but 1, so no larger number divides both.

9 = 32

12 = 22 × 3

Prime912Lowest power
2—22—
33233

— = power 0: the prime is not a factor of this number, so it cannot be in the GCF.

GCF = 3

See Also

FAQ

What is the Greatest Common Divisor of 9 and 12?

GCF (HCF) of 9 and 12 is 3

How to find the GCF of 9 and 12?

You can find the GCF of 9 and 12 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 9 and 12 is 3.

What prime factors do 9 and 12 share?

The prime factorizations of 9 and 12 have 3 in common, and multiplying those shared primes gives 3 — exactly the greatest common factor.

How does the GCF reduce the fraction 9/12?

Divide the numerator and the denominator by the GCF 3: 9 ÷ 3 = 3 and 12 ÷ 3 = 4. So 9/12 in lowest terms is 3/4.