Hi Myrna.
One way to approach the problem is to find the prime factors of each number. The greatest common factor is the product of all the prime factors both numbers have in common.
Here's an example with other figures: find the GCF of 13 340 and 156 584.
The prime factors of 13 340 are 2 x 2 x 5 x 23 x 29.
The prime factors of 156 584 are 2 x 2 x 2 x 23 x 23 x 37.
The common prime factors are 2, 2, 23, 37 (note that 2 is listed twice because each of the original numbers has at least two factors of 2).
So the greatest common factor of 13 340 and 156 584
is 2 x 2 x 23 = 92.
Hope this example helps  you can follow the same method for your own question.
Stephen La Rocque.
