Puzzles / Math 
MathNEXUS – mathy, newsy and weekly updates and problems.
http://mathnexus.wwu.edu/default.asp 
The Math
Forum @ Drexel 
www.apluscompass.com
for teacher tools 
Macalester College
POW Archive (hosted by The Math Forum @ Drexel)

Brain Teasers
from Barry R. Clarke 
Clifford
A. Pickover's Home Page

The
Fibonacci Numbers and the Golden section 
Math
History at St. Andrews 
Solve
This! – a 2003 ThinkQuest project by Aunt Claire's students,
the Vermont state winner. Follow links to library, math, and puzzles. 
Fractals
– The Mandelbrot Explorer 
Words, Logic, Other 
Puertra–
Art and Math of Isfahan 
Famous Birthdays 
Math
History at Clark 
Kelley Blue Book http://kbb.com/ 
Ken’s
Puzzle links page 
Calendars 
Archimedes’
Lab Puzzles 
Uncle Bob and Aunt Claire's Place 
Ed Pegg’s
Math Puzzles 
Methods in Mathematics: Finding the People Behind the Numbers
http://www.peoplefinders.com/articlefamouspeoplethroughouthistorymathematicians.aspx 
Number Theory
– Primepuzzles 

Eric Weisstein’s
World of Mathematics 

Math Solids Puzzles

TIP  
Nick's Math Puzzles 
Kadon Enterprises 