Not to worry, we've got 3008 and 5115. Let's get to adding them!

Step 1: We'll start by adding the digits 8 & 5 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

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

Step 3: We'll start by adding the digits 0 & 1 in column 3 and get 1.

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

So, 3008 + 5115 = 8123.

