We are presented with 6066 and 1503. Let's work out the sum.

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 6 & 0 in column 2 and get 6.

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 & 1 in column 4 and get 7.

So, 6066 + 1503 = 7569.

