LCM( 42, 63 ) = 126
Step 1 : Write the given numbers in a horizontal line.
| 42 | 63 |
Step 2 : Divide the given numbers by smallest prime number. In this example we can divide by 2.
(if any number is not divisible by 2, write it down unchanged)
| 2 | 42 | 63 |
| 21 | 63 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
| 2 | 42 | 63 |
| 3 | 21 | 63 |
| 3 | 7 | 21 |
| 7 | 7 | 7 |
| 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 42, 63 ) = 2 · 3 · 3 · 7 = 126 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.