The GCD of given numbers is 4.
Step 1 : Place the numbers inside division bar:.
| 128 | 324 |
Step 2 : Divide numbers by 2.
| 2 | 128 | 324 |
| 64 | 162 |
Step 3 : Divide numbers by 2.
| 2 | 128 | 324 |
| 2 | 64 | 162 |
| 32 | 81 |
Step 4 : Number 32 and 81, cannot be divided any more. The GCD is:
$$ GCD = 2\cdot2 = 4 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.