Solution: The GCF of 28 and 116 is 4MethodsHow to find the GCF of 28 and 116 using Prime FactorizationOne way to find the GCF of 28 and 116 is to compare the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here:What are the Factors of 28?What are the Factors of 116?Here is the prime factorization of 28:22×712^2 × 7^122×71And this is the prime factorization of 116:22×2912^2 × 29^122×291When you compare the prime factorization of these two numbers, you can see that there are matching prime factors. You can now find the Greatest Common Factor of 28 and 116 by multiplying all the matching prime factors to get a GCF of 28 and 116 as 4:Thus, the GCF of 28 and 116 is: 4How to Find the GCF of 28 and 116 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 28 and 116 is to find and list all the factors of each number. Again, you can see how this is done by looking at the “Factors of” articles that are linked to above.Let’s take a look at the factors for each of these numbers, 28 and 116:Factors of 28: 1, 2, 4, 7, 14, 28Factors of 116: 1, 2, 4, 29, 58, 116When you compare the two lists of factors, you can see that the common factor(s) are 1, 2, 4. Since 4 is the largest of these common factors, the GCF of 28 and 116 would be 4.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 5 and 110?What is the GCF of 93 and 102?What is the GCF of 16 and 47?What is the GCF of 25 and 61?What is the GCF of 49 and 48?