LCM( 4, 5 ) = 20
Step 1: Write down factorisation of each number:
4 = 2 · 2
5 = 5
Step 2 : Match primes vertically:
4 | = | 2 | · | 2 | ||
5 | = | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
4 | = | 2 | · | 2 | ||||
5 | = | 5 | ||||||
LCM | = | 2 | · | 2 | · | 5 | = | 20 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.