Find some puzzles, tricks, or
magic stunts that are based on mathematics. Write
a paper describing the tricks and also indicate
why they work. References
William Schaaf, A Bibliography
of Recreational Mathematics (Washington, D.C.:
National Council of Teachers of Mathematics, 1970).
See also the Journal of Recreational Mathematics.
Try this search engine: YAHOO Search
Results:
http://search.yahoo.com/bin/search?p=math+puzzles
(over 50 excellent sources)