No problem, let's work through this together. We're starting with 1215 and 6113 and adding them all up.

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

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

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 & 6 in column 4 and get 7.

So, 1215 + 6113 = 7328.

