LCM( 81, 9 ) = 81
Step 1 : Write the given numbers in a horizontal line.
81 | 9 |
Step 2 : Divide the given numbers by smallest prime number. In this example we can divide by 3.
(if any number is not divisible by 3, write it down unchanged)
3 | 81 | 9 |
27 | 3 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
3 | 81 | 9 |
3 | 27 | 3 |
3 | 9 | 1 |
3 | 3 | 1 |
1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 81, 9 ) = 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.