The GCD of given numbers is 10.
Step 1 :
Divide $ 1540 $ by $ 10 $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 10 }} $.
We can summarize an algorithm into a following table.
1540 | : | 10 | = | 154 | remainder ( 0 ) |
GCD = 10 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.