OK, let's do this. We've got 1024 and 8315 and we're adding them all together.

Step 1: We'll start by adding the digits 4 & 5 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 1 in column 2 and get 3.

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

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

So, 1024 + 8315 = 9339.

