LCM( 8, 7, 4 ) = 56
Step 1: Write down factorisation of each number:
8 = 2 · 2 · 2
7 = 7
4 = 2 · 2
Step 2 : Match primes vertically:
8 | = | 2 | · | 2 | · | 2 | ||
7 | = | 7 | ||||||
4 | = | 2 | · | 2 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
8 | = | 2 | · | 2 | · | 2 | ||||
7 | = | 7 | ||||||||
4 | = | 2 | · | 2 | ||||||
LCM | = | 2 | · | 2 | · | 2 | · | 7 | = | 56 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.