Alright, let's solve this problem step by step. We have 1165 and 4003 and we're adding them together.

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

Step 2: We'll start by adding the digits 6 & 0 in column 2 and get 6.

Step 3: We'll start by adding the digits 1 & 0 in column 3 and get 1.

Step 4: We'll start by adding the digits 1 & 4 in column 4 and get 5.

So, 1165 + 4003 = 5168.

