Write down the set of numbers for which you want to find the GCF.
Starting from 1, check if each number in the set is divisible by it. If all the numbers are divisible by it, mark it as a common factor.
Repeat step 2, incrementing the number by 1, until you reach the smallest number in the set.
The largest common factor that you marked in step 2 is the GCF.
This method is based on the idea of checking each number starting from 1 till the smallest number in the set and checking if it is divisible by all numbers in the set. It's a simple method that can be applied to find GCF of any set of numbers.
It's worth noting that this method may not be the most efficient way to find GCF of set of numbers, as it involves checking each number starting from 1 till the smallest number in the set. In cases where the numbers are large, more efficient methods like prime factorization and Euclidean algorithm are preferred.