No problem, let's work through this together. We're starting with 4128 and 4551 and adding them all up.

Step 1: We'll start by adding the digits 8 & 1 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 5 in column 3 and get 6.

Step 4: We'll start by adding the digits 4 & 4 in column 4 and get 8.

So, 4128 + 4551 = 8679.

