Let's break this down. We're going to add 406 and 9081 together.

Step 1: We'll start by adding the digits 6 & 1 in column 1 and get 7.

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

Step 3: We'll start by adding the digits 4 & 0 in column 3 and get 4.

Step 4: We'll start by adding the digits 0 & 9 in column 4 and get 9.

So, 406 + 9081 = 9487.

