Let's break this down. We're going to add 5015 and 3450 together.

Step 1: We'll start by adding the digits 5 & 0 in column 1 and get 5.

Step 2: We'll start by adding the digits 1 & 5 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5015 + 3450 = 8465.

