Least Common Multiple (LCM) of 21 and 12
The least common multiple (LCM) of 21 and 12 is 84.
What is the Least Common Multiple (LCM)?
The LCM of two integers is the smallest positive integer that is divisible by both numbers. It is often used to find common denominators and solve problems involving periodic events.
Formula for LCM
The LCM of two numbers can be calculated using their GCD:
LCM(a, b) = |a × b| ÷ GCD(a, b)
How to Calculate the LCM of 21 and 12?
First, calculate the GCD of 21 and 12 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 12 = 1 remainder 9 |
| 2 | 12 ÷ 9 = 1 remainder 3 |
| 3 | 9 ÷ 3 = 3 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 22 and 37 | 814 |
| 58 and 124 | 3596 |
| 40 and 144 | 720 |
| 169 and 198 | 33462 |
| 164 and 70 | 5740 |