What is GCD(73, 2)?
The GCD (Greatest Common Divisor) is the largest number that can divide two (or more) numbers without leaving a remainder.
The GCD of 73 and 2 is 1.
How to compute GCD(73, 2)
Comparing the divisors of 73 and 2
This first method consists in listing the divisors of the two numbers and then identifying the largest one they have in common.
Divisors of 73:
1, 73
Divisors of 2:
1, 2
We can see from these two lists that the greatest divisor they have in common is: 1
For small numbers, this can be done quickly. However, as numbers increase, the list of potential divisors grows longer, making this method cumbersome and less practical.
Euclid's algorithm
Fortunately, there's a much more efficient method: Euclid's algorithm. It's particularly well-suited to larger numbers. Here's how it works:
- Divide 73 by 2. The quotient is 36 and the remainder is 1.
- The previous divisor (2) is now the dividend. The remainder (1) is the new divisor. Divide 2 by 1. The quotient is 2 and the remainder is 0.
- When you reach a remainder of 0, the last divisor (in this case, 1) is the GCD.