Section 4.4 Reference Topics

What is a number? This is interesting site discussing different classifications of numbers. This site includes some types of numbers not discussed in this text, but nevertheless this is a worthwhile site.
http://www.cut-the-knot.com/do_you_know/numbers.html

Rational Numbers
http://mathworld.wolfram.com/RationalNumber.html

Teaching module on rational numbers for prospective teachers.
http://jwilson.coe.uga.edu/Texts.Folder/Tirosh/Module.html

This is an interesting enrichment site which repesents rational numbers in an artistic way. It is entitled, "A Visual Notation for Rational Numbers":
http://members.ozemail.com.au/~jatolmie/isis0.html

Links