The Greatest Common Factor
The greatest common factor (or divisor) (GCF or GCD or HCF) of a set of whole numbers is the largest positive integer that divides evenly into all numbers of that set.
For example, we have the numbers 16 and 24. One common divisor is 2 because 16/2=8 and 24/2=12. Both divisions are exact.
But 2 is not the greatest common divisor. To find the GCF, the procedure is:
* Write the prime factor of each number:
16 = 2*2*2*2
24 = 2*2*2*3
Select the maximum number of common prime factors from the numbers, even if they repeat.
We can select the product of 2*2*2 = 8 as the GCF, thus:
Answer = 8