No problem, let's work through this together. We're starting with 3129 and 5430 and adding them all up.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 3 in column 2 and get 5.

Step 3: We'll start by adding the digits 1 & 4 in column 3 and get 5.

Step 4: We'll start by adding the digits 3 & 5 in column 4 and get 8.

So, 3129 + 5430 = 8559.

