Okay, we are tasked with adding 7115 and 31. Let's begin!

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

Step 2: We'll start by adding the digits 1 & 3 in column 2 and get 4.

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 7 & 0 in column 4 and get 7.

So, 7115 + 31 = 7146.

