Okay, we are tasked with adding 8012 and 1535. Let's begin!

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

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 0 & 5 in column 3 and get 5.

Step 4: We'll start by adding the digits 8 & 1 in column 4 and get 9.

So, 8012 + 1535 = 9547.

