No problem, let's work through this together. We're starting with 503 and 414 and adding them all up.

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

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 5 & 4 in column 3 and get 9.

So, 503 + 414 = 917.

