We have numbers 1131 and 3655. Let's start adding them together.

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 3 & 5 in column 2 and get 8.

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

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

So, 1131 + 3655 = 4786.

