No problem, let's work through this together. We're starting with 1200 and 7198 and adding them all up.

Step 1: We'll start by adding the digits 0 & 8 in column 1 and get 8.

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

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

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1200 + 7198 = 8398.

