Least Common Multiple (LCM) of 81 and 123
The least common multiple (LCM) of 81 and 123 is 3321.
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 81 and 123?
First, calculate the GCD of 81 and 123 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 81 ÷ 123 = 0 remainder 81 |
| 2 | 123 ÷ 81 = 1 remainder 42 |
| 3 | 81 ÷ 42 = 1 remainder 39 |
| 4 | 42 ÷ 39 = 1 remainder 3 |
| 5 | 39 ÷ 3 = 13 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 97 and 55 | 5335 |
| 138 and 121 | 16698 |
| 23 and 80 | 1840 |
| 27 and 98 | 2646 |
| 45 and 74 | 3330 |