Tree-like Pythagorean fractal   Mark's Math
A collection of odd math bits.
  Plastic Chinese abacus
Picket 515-T slide rule
Mathematics in bloom My first calculators!


  • No matter how much math you learn there is always more to find.
    What is \(\sqrt{-1}\)?   When is 2 not a prime number?   What is \(e^{i\pi}\)?   Go Exploring.
  • Some problems to keep your life interesting.
  • I highly recommend GeoGebra, a free dynamic algebra and geometry program. Here are some quick examples of what it can do.
    The Pythagorean Tree button in the banner was created using GeoGebra.
   Spy vs. Spy The earliest papers on the use of mathematics in cryptography.