Alright, let's solve this problem step by step. We have 8300 and 815 and we're adding them together.

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

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 1.

Step 3: We'll start by adding the digits 3 & 8 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 0 in column 4 and get 9.

So, 8300 + 815 = 9115.

