Solution: The GCF of 12 and 23 is 1
Methods
How to find the GCF of 12 and 23 using Prime Factorization
One way to find the GCF of 12 and 23 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 12?
What are the Factors of 23?
Here is the prime factorization of 12:
2
2
×
3
1
2^2 × 3^1
2 2 × 3 1
And this is the prime factorization of 23:
2
3
1
23^1
2 3 1
When you compare the prime factorization of these two numbers, you can see that there are no matching prime factors. When this is the case, it means that there are no common factors between these two numbers. As a result, the GCF of 12 and 23 is 1.
Thus, the GCF of 12 and 23 is: 1
How to Find the GCF of 12 and 23 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 12 and 23 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, 12 and 23:
Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 23: 1, 23
When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 12 and 23 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 114 and 53?
What is the GCF of 133 and 99?
What is the GCF of 11 and 107?
What is the GCF of 89 and 80?
What is the GCF of 146 and 129?