LCM( 19, 3, 12, 18 ) = 684
Step 1: Write down factorisation of each number:
19 = 19
3 = 3
12 = 2 · 2 · 3
18 = 2 · 3 · 3
Step 2 : Match primes vertically:
19 | = | 19 | ||||||||
3 | = | 3 | ||||||||
12 | = | 2 | · | 2 | · | 3 | ||||
18 | = | 2 | · | 3 | · | 3 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
19 | = | 19 | ||||||||||
3 | = | 3 | ||||||||||
12 | = | 2 | · | 2 | · | 3 | ||||||
18 | = | 2 | · | 3 | · | 3 | ||||||
LCM | = | 2 | · | 2 | · | 3 | · | 3 | · | 19 | = | 684 |