GCF(81, 72) = 9
GCD is equal to the product of the common prime factors on the left side of the cake above.
GCF(81, 72) = 3 . 3 = 9
The common factors of 81 and 72 are 1, 3 and 9. Among these numbers, the greatest one is 9
The greatest common factor (GCF) of two positive whole numbers is the largest number that divides these numbers exactly. GCF can be found by using the upside-down cake method. It is equal to the product of the common prime factors listed on the left.