LCM( 2, 3, 5, 7 ) = 210
Step 1: Write down factorisation of each number:
2 = 2
3 = 3
5 = 5
7 = 7
Step 2 : Match primes vertically:
2 | = | 2 | ||||||
3 | = | 3 | ||||||
5 | = | 5 | ||||||
7 | = | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
2 | = | 2 | ||||||||
3 | = | 3 | ||||||||
5 | = | 5 | ||||||||
7 | = | 7 | ||||||||
LCM | = | 2 | · | 3 | · | 5 | · | 7 | = | 210 |