Greatest Common Divisor (GCD) of 168 and 189
The greatest common divisor (GCD) of 168 and 189 is 21.
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 168 and 189?
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 | 168 ÷ 189 = 0 remainder 168 |
| 2 | 189 ÷ 168 = 1 remainder 21 |
| 3 | 168 ÷ 21 = 8 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 73 and 145 | 1 |
| 119 and 165 | 1 |
| 152 and 195 | 1 |
| 38 and 195 | 1 |
| 142 and 147 | 1 |