Alright, let's solve this problem step by step. We have 4011 and 4928 and we're adding them together.

Step 1: We'll start by adding the digits 1 & 8 in column 1 and get 9.

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

Step 3: We'll start by adding the digits 0 & 9 in column 3 and get 9.

Step 4: We'll start by adding the digits 4 & 4 in column 4 and get 8.

So, 4011 + 4928 = 8939.

