Calculate R:

   1 point -- provides code attempting the question
   2 points -- reports the result of r or code prints this result

   2 points -- correctly calculate r



Turn To Closest Cube:

   3 -- points for finding the closest cube

   1.5 -- points for turning

   0.5 -- correctly calculated turn angle (need to calculate bearing
   and then subtract current robot heading)

   We may have to change 4 students grades in the case they are using a
   method to find r that I am unfamiliar with, and I have sent you a
   separate email about this.