Least Common Multiple (LCM) of 21 and 27
The least common multiple (LCM) of 21 and 27 is 189.
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 27?
First, calculate the GCD of 21 and 27 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 27 = 0 remainder 21 |
| 2 | 27 ÷ 21 = 1 remainder 6 |
| 3 | 21 ÷ 6 = 3 remainder 3 |
| 4 | 6 ÷ 3 = 2 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 102 and 56 | 2856 |
| 169 and 185 | 31265 |
| 128 and 142 | 9088 |
| 191 and 184 | 35144 |
| 38 and 138 | 2622 |