Solution: The LCM of 140 and 47 is 6580
Methods
How to find the LCM of 140 and 47 using Prime Factorization
One way to find the LCM of 140 and 47 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 140?
What are the Factors of 47?
Here is the prime factorization of 140:
2
2
×
5
1
×
7
1
2^2 × 5^1 × 7^1
2 2 × 5 1 × 7 1
And this is the prime factorization of 47:
4
7
1
47^1
4 7 1
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, 47
2
2
×
5
1
×
7
1
×
4
7
1
=
6580
2^2 × 5^1 × 7^1 × 47^1 = 6580
2 2 × 5 1 × 7 1 × 4 7 1 = 6580
Through this we see that the LCM of 140 and 47 is 6580.
How to Find the LCM of 140 and 47 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 140 and 47 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, 140 and 47:
What are the Multiples of 140?
What are the Multiples of 47?
Let’s take a look at the first 10 multiples for each of these numbers, 140 and 47:
First 10 Multiples of 140: 140, 280, 420, 560, 700, 840, 980, 1120, 1260, 1400
First 10 Multiples of 47: 47, 94, 141, 188, 235, 282, 329, 376, 423, 470
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 140 and 47 are 6580, 13160, 19740. Because 6580 is the smallest, it is the least common multiple.
The LCM of 140 and 47 is 6580.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 23 and 89?
What is the LCM of 72 and 1?
What is the LCM of 82 and 17?
What is the LCM of 67 and 142?
What is the LCM of 95 and 68?