In my version of the code, I created a variable called flat_charge at the top of the program instead of adding + 20 in every line of the Ground Shipping calculation.

This approach makes the code:

Cleaner and easier to read – the flat charge is clearly defined once, rather than repeated.

Easier to update – if the flat charge ever changes (for example, from $20 to $25), it only needs to be updated in one place.

More maintainable – helps prevent typing mistakes or inconsistencies if the same value appears multiple times.