Let's solve this addition problem. We have 104 and 115, and we need to add them together.

Step 1: We'll start by adding the digits 4 & 5 in column 1 and get 9.

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 1.

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

So, 104 + 115 = 219.

