No problem, let's work through this together. We're starting with 1043 and 7421 and adding them all up.

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

Step 2: We'll start by adding the digits 4 & 2 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1043 + 7421 = 8464.

