Let's break this down. We're going to add 1000 and 443 together.

Step 1: We'll start by adding the digits 0 & 3 in column 1 and get 3.

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 4.

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

Step 4: We'll start by adding the digits 1 & 0 in column 4 and get 1.

So, 1000 + 443 = 1443.

