Solution: The LCM of 31 and 100 is 3100
Methods
How to find the LCM of 31 and 100 using Prime Factorization
One way to find the LCM of 31 and 100 is to start by comparing 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 31?
What are the Factors of 100?
Here is the prime factorization of 31:
3
1
1
31^1
3 1 1
And this is the prime factorization of 100:
2
2
×
5
2
2^2 × 5^2
2 2 × 5 2
When you compare the prime factorization of these two numbers, you want to look for the highest power that each prime factor is raised to. In this case, there are these prime factors to consider: 31, 2, 5
2
2
×
5
2
×
3
1
1
=
3100
2^2 × 5^2 × 31^1 = 3100
2 2 × 5 2 × 3 1 1 = 3100
Through this we see that the LCM of 31 and 100 is 3100.
How to Find the LCM of 31 and 100 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 31 and 100 is to begin to list a few multiples for each number. If you need a refresher on how to find the multiples of these numbers, you can see the walkthroughs in the links below for each number.
Let’s take a look at the multiples for each of these numbers, 31 and 100:
What are the Multiples of 31?
What are the Multiples of 100?
Let’s take a look at the first 10 multiples for each of these numbers, 31 and 100:
First 10 Multiples of 31: 31, 62, 93, 124, 155, 186, 217, 248, 279, 310
First 10 Multiples of 100: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000
You can continue to list out the multiples of these numbers as long as needed to find a match. Once you do find a match, or several matches, the smallest of these matches would be the Least Common Multiple. For instance, the first matching multiple(s) of 31 and 100 are 3100, 6200, 9300. Because 3100 is the smallest, it is the least common multiple.
The LCM of 31 and 100 is 3100.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 38 and 94?
What is the LCM of 57 and 72?
What is the LCM of 89 and 33?
What is the LCM of 116 and 7?
What is the LCM of 85 and 1?