Not to worry, we've got 7581 and 1200. Let's get to adding them!

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

Step 2: We'll start by adding the digits 8 & 0 in column 2 and get 8.

Step 3: We'll start by adding the digits 5 & 2 in column 3 and get 7.

Step 4: We'll start by adding the digits 7 & 1 in column 4 and get 8.

So, 7581 + 1200 = 8781.

