The GCD of given numbers is 1.
Step 1 :
Divide $ 880 $ by $ 21 $ and get the remainder
The remainder is positive ($ 19 > 0 $), so we will continue with division.
Step 2 :
Divide $ 21 $ by $ \color{blue}{ 19 } $ and get the remainder
The remainder is still positive ($ 2 > 0 $), so we will continue with division.
Step 3 :
Divide $ 19 $ by $ \color{blue}{ 2 } $ and get the remainder
The remainder is still positive ($ 1 > 0 $), so we will continue with division.
Step 4 :
Divide $ 2 $ by $ \color{blue}{ 1 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 1 }} $.
We can summarize an algorithm into a following table.
880 | : | 21 | = | 41 | remainder ( 19 ) | ||||||
21 | : | 19 | = | 1 | remainder ( 2 ) | ||||||
19 | : | 2 | = | 9 | remainder ( 1 ) | ||||||
2 | : | 1 | = | 2 | remainder ( 0 ) | ||||||
GCD = 1 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.