Let's break this down. We're going to add 5366 and 3633 together.

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 6 & 3 in column 2 and get 9.

Step 3: We'll start by adding the digits 3 & 6 in column 3 and get 9.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5366 + 3633 = 8999.

