Let's break this down. We're going to add 4104 and 4071 together.

Step 1: We'll start by adding the digits 4 & 1 in column 1 and get 5.

Step 2: We'll start by adding the digits 0 & 7 in column 2 and get 7.

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 4 & 4 in column 4 and get 8.

So, 4104 + 4071 = 8175.

