The GCD of given numbers is 16.
Step 1 :
Divide $ 64 $ by $ 16 $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 16 }} $.
We can summarize an algorithm into a following table.
64 | : | 16 | = | 4 | remainder ( 0 ) |
GCD = 16 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.