Let's break this down. We're going to add 143 and 3442 together.

Step 1: We'll start by adding the digits 3 & 2 in column 1 and get 5.

Step 2: We'll start by adding the digits 4 & 4 in column 2 and get 8.

Step 3: We'll start by adding the digits 1 & 4 in column 3 and get 5.

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

So, 143 + 3442 = 3585.

