Okay, we are given 6017 and 503. Let's add them up step by step.

Step 1: We'll start by adding the digits 7 & 3 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 1 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 0 & 5 in column 3 and get 5.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6017 + 503 = 6520.

