Alright, let's solve this problem step by step. We have 3211 and 306 and we're adding them together.

Step 1: We'll start by adding the digits 1 & 6 in column 1 and get 7.

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

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

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

So, 3211 + 306 = 3517.

