Let's break this down. We're going to add 1615 and 3310 together.

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

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

Step 3: We'll start by adding the digits 6 & 3 in column 3 and get 9.

Step 4: We'll start by adding the digits 1 & 3 in column 4 and get 4.

So, 1615 + 3310 = 4925.

