How do you find the gcf of 2 numbers

To find the GCF of two numbers, list all the factors of those numbers, then underline all the matching factors, and finally find the grates common factor.

Example:

GCF (30, 25) = x

30: 1,2,3,5,6,10,15,30

25: 1,5,25

Common Factors: 1, 5

Greatest Common Factor: 5

x=5

GCF (30,25) = 5

You need to find what numbers can multiply to make that number. I hope this makes sense