Find the greatest common factor of 210, 84, and 56

To get the Greates Common Factor (GCF) of 84 and 210 we need to factor each value first and then we choose all the copies of factors and multiply them:

84: 223 7 210: 2 357 GCF: 2 3 7

The Greates Common Factor (GCF) is: 2 x 3 x 7 = 42

Write the prime factors:-

56 = 2*2*2*7

84 = 2*2*3*7

210 = 2*3*5*7

Pick out the numbers common to all three factors;

They are 2 and 7.

So the GCF = 2*7 = 14 answer