No problem, let's work through this together. We're starting with 528 and 349 and adding them all up.

Step 1: We'll start by adding the digits 8 & 9 in column 1 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 4 in column 2 and get 7.

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

So, 528 + 349 = 877.

