Solution: The LCM of 70 and 32 is 1120
Methods
How to find the LCM of 70 and 32 using Prime Factorization
One way to find the LCM of 70 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 70?
What are the Factors of 32?
Here is the prime factorization of 70:
2
1
×
5
1
×
7
1
2^1 × 5^1 × 7^1
2 1 × 5 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 want to look for the highest power that each prime factor is raised to. In this case, there are these prime factors to consider: 2, 5, 7
2
5
×
5
1
×
7
1
=
1120
2^5 × 5^1 × 7^1 = 1120
2 5 × 5 1 × 7 1 = 1120
Through this we see that the LCM of 70 and 32 is 1120.
How to Find the LCM of 70 and 32 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 70 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, 70 and 32:
What are the Multiples of 70?
What are the Multiples of 32?
Let’s take a look at the first 10 multiples for each of these numbers, 70 and 32:
First 10 Multiples of 70: 70, 140, 210, 280, 350, 420, 490, 560, 630, 700
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 70 and 32 are 1120, 2240, 3360. Because 1120 is the smallest, it is the least common multiple.
The LCM of 70 and 32 is 1120.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 25 and 123?
What is the LCM of 75 and 31?
What is the LCM of 14 and 87?
What is the LCM of 10 and 139?
What is the LCM of 121 and 34?