Let's break this down. We're going to add 30 and 7455 together.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

Step 2: We'll start by adding the digits 3 & 5 in column 2 and get 8.

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 0 & 7 in column 4 and get 7.

So, 30 + 7455 = 7485.

