Okay, we are tasked with adding 6631 and 3302. Let's begin!

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 3 & 0 in column 2 and get 3.

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 6 & 3 in column 4 and get 9.

So, 6631 + 3302 = 9933.

