LCM( 9, 81, 3 ) = 81
Step 1: Write down factorisation of each number:
9 = 3 · 3
81 = 3 · 3 · 3 · 3
3 = 3
Step 2 : Match primes vertically:
9 | = | 3 | · | 3 | ||||
81 | = | 3 | · | 3 | · | 3 | · | 3 |
3 | = | 3 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
9 | = | 3 | · | 3 | ||||||
81 | = | 3 | · | 3 | · | 3 | · | 3 | ||
3 | = | 3 | ||||||||
LCM | = | 3 | · | 3 | · | 3 | · | 3 | = | 81 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.