LCM( 4, 7, 10 ) = 140
Step 1: Write down factorisation of each number:
4 = 2 · 2
7 = 7
10 = 2 · 5
Step 2 : Match primes vertically:
4 | = | 2 | · | 2 | ||||
7 | = | 7 | ||||||
10 | = | 2 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
4 | = | 2 | · | 2 | ||||||
7 | = | 7 | ||||||||
10 | = | 2 | · | 5 | ||||||
LCM | = | 2 | · | 2 | · | 5 | · | 7 | = | 140 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.