How do find the greatest common divisor?

Answer 1

The Greatest Common Divisor is the number that divides all the given numbers evenly (with a reminder of '0') and also is the greatest of all possible divisors that are common to all the numbers.

Step 1: Identify all the factors/divisors of the numbers

Step 2: Select only the numbers that are common factors for all the given input numbers

Step 3: Choose the greatest of the factors and select it as the GCD

Answer 2

Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF