GCF (HCF) of 78 and 100

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 78 and 100?

Answer

GCF (HCF) of 78 and 100 is
2

Common factors: 1, 2

2 divides both: 78 ÷ 2 = 39, 100 ÷ 2 = 50 — and 39 and 50 share no factor but 1, so no larger number divides both.

78 = 2 × 3 × 13

100 = 22 × 52

Prime78100Lowest power
22222
33——
5—52—
1313——

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

GCF = 2

See Also

GCF Table

Number 1Number 2GCF
78851
78862
78873
78882
78891
78906
789113
78922
78933
78942
78951
78966
78971
78982
78993
781002
781011
781026
781031
7810426
781053
781062
781071
781086
781091
781102
781113
781122
781131
781146

FAQ

What is the Greatest Common Divisor of 78 and 100?

GCF (HCF) of 78 and 100 is 2

How to find the GCF of 78 and 100?

You can find the GCF of 78 and 100 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 78 and 100 is 2.

What prime factors do 78 and 100 share?

The prime factorizations of 78 and 100 have 2 in common, and multiplying those shared primes gives 2 — exactly the greatest common factor.

How does the GCF reduce the fraction 78/100?

Divide the numerator and the denominator by the GCF 2: 78 ÷ 2 = 39 and 100 ÷ 2 = 50. So 78/100 in lowest terms is 39/50.