Let's break this down. We're going to add 2400 and 4142 together.

Step 1: We'll start by adding the digits 0 & 2 in column 1 and get 2.

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 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 2 & 4 in column 4 and get 6.

So, 2400 + 4142 = 6542.

