1. Movie Rater

2. Create a page to allow a user to rate movies (or anything)

3. When user changes value in drop-down select then use a loop to display the corresponding number of stars

4. If user clicks the calculate button at bottom, then loop through their rates and display an average

5. Finer points
If the user does not rate a movie, skip it in calculating the average. (In your loop sum up the rates and count up the number of rates, then when the loop is done divide the sum by the count.)
If the user changes a rate, then clear out any displayed average.