Let's break this down. We're going to add 121 and 9761 together.

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

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

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

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

So, 121 + 9761 = 9882.

