Let's break this down. We're going to add 3646 and 1353 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 4 & 5 in column 2 and get 9.

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

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

So, 3646 + 1353 = 4999.

