Let's break this down. We're going to add 681 and 6203 together.

Step 1: We'll start by adding the digits 1 & 3 in column 1 and get 4.

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 6 & 2 in column 3 and get 8.

Step 4: We'll start by adding the digits 0 & 6 in column 4 and get 6.

So, 681 + 6203 = 6884.

