Let's break this down. We're going to add 613 and 7374 together.

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

Step 2: We'll start by adding the digits 1 & 7 in column 2 and get 8.

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 0 & 7 in column 4 and get 7.

So, 613 + 7374 = 7987.

