LCM( 16, 20 ) = 80
Step 1: Write down factorisation of each number:
16 = 2 · 2 · 2 · 2
20 = 2 · 2 · 5
Step 2 : Match primes vertically:
16 | = | 2 | · | 2 | · | 2 | · | 2 | ||
20 | = | 2 | · | 2 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
16 | = | 2 | · | 2 | · | 2 | · | 2 | ||||
20 | = | 2 | · | 2 | · | 5 | ||||||
LCM | = | 2 | · | 2 | · | 2 | · | 2 | · | 5 | = | 80 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.