Greatest Common Divisor (GCD) of 177 and 42
The greatest common divisor (GCD) of 177 and 42 is 3.
What is the Greatest Common Divisor (GCD)?
The GCD of two integers is the largest positive integer that divides both numbers without leaving a remainder. It is useful in simplifying fractions, finding common factors, and in number theory.
How to Calculate the GCD of 177 and 42?
We use the Euclidean algorithm, which involves the following steps:
- Divide the larger number by the smaller number.
- Replace the larger number with the smaller number and the smaller number with the remainder from the division.
- Repeat this process until the remainder is zero.
- The non-zero remainder just before zero is the GCD.
Step-by-Step Euclidean Algorithm
| Step | Calculation |
|---|---|
| 1 | 177 ÷ 42 = 4 remainder 9 |
| 2 | 42 ÷ 9 = 4 remainder 6 |
| 3 | 9 ÷ 6 = 1 remainder 3 |
| 4 | 6 ÷ 3 = 2 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 86 and 29 | 1 |
| 138 and 172 | 2 |
| 75 and 142 | 1 |
| 118 and 20 | 2 |
| 91 and 79 | 1 |