Be forewarned that some pages are heavy laden with (mostly very small) graphics, and that no page can be fully enjoyed without displaying its graphics.
An elementary discussion of infinite sets, including both countable and uncountable sets.
A famous and quite curious construction of an infinite set based on the nested interval theorem.
An ancient technique for computing square roots that has evolved into an effective computer algorithm for computing all manner of transcendental functions.
Closely related to the Babylonian algorithm is Archimedes' algorithm for computing Pi. I also discuss the pre-computer history of Pi and list several cool formulas for Pi. These pages won StudyWeb's Academic Excellence Award.