Here is some more information about the sensor. If you decide to share it with your students, you should definitely show them the video below at 4:26 where we demonstrate a rotation sensor backlash.
When we program the robot to move really quickly for a certain distance, it usually goes a little further. Then the sensor sends a signal to the robot which turns a little backward. That is the explanation why the robot goes back a little sometimes. You can see this in the video below: https://www.fllcasts.com/tutorials/54-how-to-on-gears-part-1