Let's break this down. We're going to add 291 and 7602 together.

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

Step 2: We'll start by adding the digits 9 & 0 in column 2 and get 9.

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

Step 4: We'll start by adding the digits 0 & 7 in column 4 and get 7.

So, 291 + 7602 = 7893.

