If you no longer wish to save your old scores in your student file you may erase your scores page. The next time you save your student file only new scores will be saved.
Use the Actions Menu on the Scores Page.
A warning box will appear:
Make a backup file before doing this. Then you will be able to review your old scores anytime in the future to see which drills were the most difficult for you. This gives you a starting place for review. Use Main Menu - Pick a Drill and Practice Mode to review any level.