Greatest Common Divisor (GCD) of 153 and 189
The greatest common divisor (GCD) of 153 and 189 is 9.
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 153 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 | 153 ÷ 189 = 0 remainder 153 |
| 2 | 189 ÷ 153 = 1 remainder 36 |
| 3 | 153 ÷ 36 = 4 remainder 9 |
| 4 | 36 ÷ 9 = 4 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 168 and 21 | 21 |
| 162 and 98 | 2 |
| 165 and 86 | 1 |
| 108 and 165 | 3 |
| 172 and 157 | 1 |