Least Common Multiple (LCM) of 21 and 84
The least common multiple (LCM) of 21 and 84 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 84?
First, calculate the GCD of 21 and 84 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 84 = 0 remainder 21 |
| 2 | 84 ÷ 21 = 4 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 106 and 131 | 13886 |
| 136 and 24 | 408 |
| 98 and 76 | 3724 |
| 106 and 21 | 2226 |
| 29 and 74 | 2146 |