Least Common Multiple (LCM) of 21 and 70
The least common multiple (LCM) of 21 and 70 is 210.
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 70?
First, calculate the GCD of 21 and 70 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 70 = 0 remainder 21 |
| 2 | 70 ÷ 21 = 3 remainder 7 |
| 3 | 21 ÷ 7 = 3 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 136 and 24 | 408 |
| 179 and 117 | 20943 |
| 73 and 67 | 4891 |
| 42 and 64 | 1344 |
| 51 and 138 | 2346 |