Not to worry, we've got 8241 and 7635. Let's get to adding them!

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

Step 2: We'll start by adding the digits 4 & 3 in column 2 and get 7.

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

Step 4: We'll start by adding the digits 8 & 7 in column 4 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

So, 8241 + 7635 = 15876.

