Least Common Multiple (LCM) of 81 and 49
The least common multiple (LCM) of 81 and 49 is 3969.
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 49?
First, calculate the GCD of 81 and 49 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 81 ÷ 49 = 1 remainder 32 |
| 2 | 49 ÷ 32 = 1 remainder 17 |
| 3 | 32 ÷ 17 = 1 remainder 15 |
| 4 | 17 ÷ 15 = 1 remainder 2 |
| 5 | 15 ÷ 2 = 7 remainder 1 |
| 6 | 2 ÷ 1 = 2 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 73 and 178 | 12994 |
| 145 and 72 | 10440 |
| 171 and 142 | 24282 |
| 22 and 30 | 330 |
| 100 and 36 | 900 |