Step 1 : Find prime factorization of each number.

$$\begin{aligned}290 =& 2\cdot5\cdot29\\[8pt]290 =& 2\cdot5\cdot29\\[8pt]\end{aligned}$$

(view steps on how to factor 290 and 290. )

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

$$\begin{aligned}290 =& \color{blue}{\boxed{2}}\cdot\color{red}{\boxed{5}}\cdot\color{Fuchsia}{\boxed{29}}\\[8pt]290 =& \color{blue}{\boxed{2}}\cdot\color{red}{\boxed{5}}\cdot\color{Fuchsia}{\boxed{29}}\\[8pt]\end{aligned}$$

Step 3 : Multiply the boxed numbers together:

$$ GCD = 2\cdot5\cdot29 = 290 $$

This solution can be visualized using a Venn diagram.

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

GCD Calculator