Hi Dr. Newton,

Although exponents and radicals are a form of arithmetic, involving multiplication and division, these topics are a bit more advanced that just multiplication and division.  The most likely reason they aren't included in the Arithmetic course is so users are more prepared for it when they are old enough and in the right grade level to understand it.  Radicals especially would most likely be very difficult for elementary or early middle school students to understand, but when they are old enough and have entered the correct grade level, they would have a better chance at understanding the concept.

Thank you for the feedback!

Elijah