Least Common Multiple (LCM) of 90 and 21
The least common multiple (LCM) of 90 and 21 is 630.
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 90 and 21?
First, calculate the GCD of 90 and 21 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 90 ÷ 21 = 4 remainder 6 |
| 2 | 21 ÷ 6 = 3 remainder 3 |
| 3 | 6 ÷ 3 = 2 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 177 and 140 | 24780 |
| 77 and 89 | 6853 |
| 142 and 164 | 11644 |
| 101 and 78 | 7878 |
| 105 and 33 | 1155 |