Here we go! We're going to add 521 and 2202 together.

Step 1: We'll start by adding the digits 1 & 2 in column 1 and get 3.

Step 2: We'll start by adding the digits 2 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 5 & 2 in column 3 and get 7.

Step 4: We'll start by adding the digits 0 & 2 in column 4 and get 2.

So, 521 + 2202 = 2723.

