Let's break this down. We're going to add 7621 and 1 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 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 6.

Step 4: We'll start by adding the digits 7 & 0 in column 4 and get 7.

So, 7621 + 1 = 7622.

