Let's solve this addition problem. We have 790 and 200, and we need to add them together.

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

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 7 & 2 in column 3 and get 9.

So, 790 + 200 = 990.

