Least Common Multiple (LCM) of 21 and 140
The least common multiple (LCM) of 21 and 140 is 420.
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 140?
First, calculate the GCD of 21 and 140 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 140 = 0 remainder 21 |
| 2 | 140 ÷ 21 = 6 remainder 14 |
| 3 | 21 ÷ 14 = 1 remainder 7 |
| 4 | 14 ÷ 7 = 2 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 123 and 14 | 1722 |
| 70 and 41 | 2870 |
| 53 and 44 | 2332 |
| 49 and 168 | 1176 |
| 115 and 72 | 8280 |