Find Greatest Common Divisor of 3556 and 3444, using prime factorization.

Step 1 : Find prime factorization of each number.

$$\begin{aligned}3556 =& 2\cdot2\cdot7\cdot127\\[8pt]3444 =& 2\cdot2\cdot3\cdot7\cdot41\\[8pt]\end{aligned}$$

(view steps on how to factor 3556 and 3444. )

Step 2 : Put a box around factors that are common for all numbers:

$$\begin{aligned}3556 =& \color{blue}{\boxed{2}}\cdot\color{red}{\boxed{2}}\cdot\color{Fuchsia}{\boxed{7}}\cdot127\\[8pt]3444 =& \color{blue}{\boxed{2}}\cdot\color{red}{\boxed{2}}\cdot3\cdot\color{Fuchsia}{\boxed{7}}\cdot41\\[8pt]\end{aligned}$$

Step 3 : Multiply the boxed numbers together:

$$ GCD = 2\cdot2\cdot7 = 28 $$

This solution can be visualized using a Venn diagram.

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

GCD Calculator