Alright, let's solve this problem step by step. We have 604 and 9012 and we're adding them together.

Step 1: We'll start by adding the digits 4 & 2 in column 1 and get 6.

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 6 & 0 in column 3 and get 6.

Step 4: We'll start by adding the digits 0 & 9 in column 4 and get 9.

So, 604 + 9012 = 9616.

