LCM( 168, 30 ) = 840
Step 1: Write down factorisation of each number:
168 = 2 · 2 · 2 · 3 · 7
30 = 2 · 3 · 5
Step 2 : Match primes vertically:
168 | = | 2 | · | 2 | · | 2 | · | 3 | · | 7 | ||
30 | = | 2 | · | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
168 | = | 2 | · | 2 | · | 2 | · | 3 | · | 7 | ||||
30 | = | 2 | · | 3 | · | 5 | ||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 5 | · | 7 | = | 840 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.