How do you find the GCF in two numbers?

Answer:
The prime factorization of 210 is 2 x 3 x 5 x 7
The prime factorization of 1890 is 2 x 3 x 5 x 7 x 9
The largest number in common out of those two sets is 5.
That's the GCF.
First answer by Depresedsasian72. Last edit by Ericbarnes. Contributor trust: 140 [recommend contributor recommended]. Question popularity: 1 [recommend question].