The GCD of given numbers is 18.
Step 1 :
Divide $ 486 $ by $ 18 $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 18 }} $.
We can summarize an algorithm into a following table.
486 | : | 18 | = | 27 | remainder ( 0 ) |
GCD = 18 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.