Okay, we are tasked with adding 3111 and 6255. Let's begin!

Step 1: We'll start by adding the digits 1 & 5 in column 1 and get 6.

Step 2: We'll start by adding the digits 1 & 5 in column 2 and get 6.

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

Step 4: We'll start by adding the digits 3 & 6 in column 4 and get 9.

So, 3111 + 6255 = 9366.

