Okay, we are tasked with adding 1131 and 6303. Let's begin!

Step 1: We'll start by adding the digits 1 & 3 in column 1 and get 4.

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 1 & 3 in column 3 and get 4.

Step 4: We'll start by adding the digits 1 & 6 in column 4 and get 7.

So, 1131 + 6303 = 7434.

