        “But ten isn’t a very logical stopping point.  It must be terrible at math.  It can’t divide evenly by three or four.  Its foals must have a terrible time learning fractions.”  Twilight shuddered.  “A third would be endlessly repeating.  At least with our number system, only sevenths have that property.”  She scribbled for a moment on a scrap of parchment.  “It does with ten, too.  Oh, that’s interesting!  I wonder if my math professor knows?”