Let's break this down. We're going to add 1506 and 5220 together.

Step 1: We'll start by adding the digits 6 & 0 in column 1 and get 6.

Step 2: We'll start by adding the digits 0 & 2 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 1 & 5 in column 4 and get 6.

So, 1506 + 5220 = 6726.

