Step 1 :
Divide $ 11992872 $ by $ 1190940 $ and get the remainder

$$ 11992872 : 1190940 = 10 \text{ ( remainder is } \color{blue}{ 83472 } \text{ ) } $$

The remainder is positive ($ 83472 > 0 $), so we will continue with division.

Step 2 :
Divide $ 1190940 $ by $ \color{blue}{ 83472 } $ and get the remainder

$$ 1190940 : 83472 = 14 \text{ ( remainder is } \color{blue}{ 22332 } \text{ ) } $$

The remainder is still positive ($ 22332 > 0 $), so we will continue with division.

Step 3 :
Divide $ 83472 $ by $ \color{blue}{ 22332 } $ and get the remainder

$$ 83472 : 22332 = 3 \text{ ( remainder is } \color{blue}{ 16476 } \text{ ) } $$

The remainder is still positive ($ 16476 > 0 $), so we will continue with division.

Step 4 :
Divide $ 22332 $ by $ \color{blue}{ 16476 } $ and get the remainder

$$ 22332 : 16476 = 1 \text{ ( remainder is } \color{blue}{ 5856 } \text{ ) } $$

The remainder is still positive ($ 5856 > 0 $), so we will continue with division.

Step 5 :
Divide $ 16476 $ by $ \color{blue}{ 5856 } $ and get the remainder

$$ 16476 : 5856 = 2 \text{ ( remainder is } \color{blue}{ 4764 } \text{ ) } $$

The remainder is still positive ($ 4764 > 0 $), so we will continue with division.

Step 6 :
Divide $ 5856 $ by $ \color{blue}{ 4764 } $ and get the remainder

$$ 5856 : 4764 = 1 \text{ ( remainder is } \color{blue}{ 1092 } \text{ ) } $$

The remainder is still positive ($ 1092 > 0 $), so we will continue with division.

Step 7 :
Divide $ 4764 $ by $ \color{blue}{ 1092 } $ and get the remainder

$$ 4764 : 1092 = 4 \text{ ( remainder is } \color{blue}{ 396 } \text{ ) } $$

The remainder is still positive ($ 396 > 0 $), so we will continue with division.

Step 8 :
Divide $ 1092 $ by $ \color{blue}{ 396 } $ and get the remainder

$$ 1092 : 396 = 2 \text{ ( remainder is } \color{blue}{ 300 } \text{ ) } $$

The remainder is still positive ($ 300 > 0 $), so we will continue with division.

Step 9 :
Divide $ 396 $ by $ \color{blue}{ 300 } $ and get the remainder

$$ 396 : 300 = 1 \text{ ( remainder is } \color{blue}{ 96 } \text{ ) } $$

The remainder is still positive ($ 96 > 0 $), so we will continue with division.

Step 10 :
Divide $ 300 $ by $ \color{blue}{ 96 } $ and get the remainder

$$ 300 : 96 = 3 \text{ ( remainder is } \color{blue}{ 12 } \text{ ) } $$

The remainder is still positive ($ 12 > 0 $), so we will continue with division.

Step 11 :
Divide $ 96 $ by $ \color{blue}{ 12 } $ and get the remainder

$$ 96 : \color{blue}{ \boxed { 12 }} = 8 \text{ ( remainder is } \color{blue}{ 0 } \text{ ) } $$

The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 12 }} $.

This solution can be visualized using a Venn diagram.

The GCD equals the product of the numbers at the intersection.

GCD Calculator