Solution: The LCM of 45 and 32 is 1440
Methods
How to find the LCM of 45 and 32 using Prime Factorization
One way to find the LCM of 45 and 32 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 45?
What are the Factors of 32?
Here is the prime factorization of 45:
3
2
×
5
1
3^2 × 5^1
3 2 × 5 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 want to look for the highest power that each prime factor is raised to. In this case, there are these prime factors to consider: 3, 5, 2
2
5
×
3
2
×
5
1
=
1440
2^5 × 3^2 × 5^1 = 1440
2 5 × 3 2 × 5 1 = 1440
Through this we see that the LCM of 45 and 32 is 1440.
How to Find the LCM of 45 and 32 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 45 and 32 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, 45 and 32:
What are the Multiples of 45?
What are the Multiples of 32?
Let’s take a look at the first 10 multiples for each of these numbers, 45 and 32:
First 10 Multiples of 45: 45, 90, 135, 180, 225, 270, 315, 360, 405, 450
First 10 Multiples of 32: 32, 64, 96, 128, 160, 192, 224, 256, 288, 320
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 45 and 32 are 1440, 2880, 4320. Because 1440 is the smallest, it is the least common multiple.
The LCM of 45 and 32 is 1440.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 20 and 47?
What is the LCM of 88 and 139?
What is the LCM of 15 and 128?
What is the LCM of 19 and 27?
What is the LCM of 150 and 141?