How do I total up points every time user returns to menu slide?

Hello. I have a course with a custom menu slide. Users have 8 lessons listed on the menu slide. Users must take lessons in order. Within each lesson, there are links or objects users can click on to earn points (for added interaction). Each clickable item earns 10 points. When a user completes a lesson, they are returned to the menu slide, and the total points earned display at bottom of screen using a %totalpoints% placeholder. Each time they click out to a new lesson, the totalpoints on the menu slide is set to 0.00. Each time the user returns to the slide, the totalpoints displays the new total. The problem is, when users have completed all lessons, if they decided to repeat a lesson, the total points on the menu slide start increasing in increments of the total points after lesson 8 was completed. So if they earn 100 points after completing all 8 lessons and repeat a lesson, the menu slide will display 200 points. I can't turn off the points total. Is there an easier way to have a running total of points on the menu slide that stop adding points at a certain point. Currently I am adding 10 points to totalpoints for each variable that is clicked and set to 10.  Should I be using True False variables?