Let's solve this addition problem. We have 1509 and 5080, and we need to add them together.

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 0 & 8 in column 2 and get 8.

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

Step 4: We'll start by adding the digits 1 & 5 in column 4 and get 6.

So, 1509 + 5080 = 6589.

