Let's break this down. We're going to add 3323 and 612 together.

Step 1: We'll start by adding the digits 3 & 2 in column 1 and get 5.

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

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

Step 4: We'll start by adding the digits 3 & 0 in column 4 and get 3.

So, 3323 + 612 = 3935.

