Solution: The GCF of 84 and 32 is 4
Methods
How to find the GCF of 84 and 32 using Prime Factorization
One way to find the GCF of 84 and 32 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 84?
What are the Factors of 32?
Here is the prime factorization of 84:
2
2
×
3
1
×
7
1
2^2 × 3^1 × 7^1
2 2 × 3 1 × 7 1
And this is the prime factorization of 32:
2
5
2^5
2 5
When 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 84 and 32 by multiplying all the matching prime factors to get a GCF of 84 and 32 as 4:
Thus, the GCF of 84 and 32 is: 4
How to Find the GCF of 84 and 32 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 84 and 32 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, 84 and 32:
Factors of 84: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
Factors of 32: 1, 2, 4, 8, 16, 32
When 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 84 and 32 would be 4.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 41 and 142?
What is the GCF of 91 and 40?
What is the GCF of 124 and 47?
What is the GCF of 25 and 9?
What is the GCF of 82 and 37?