Math tricks?

Question

Whats a good site that has cool math tricks??? My teacher showed me something cool today and I am now addicted to finding cool math tricks!

Answer 1

i know a good one!
http://www.angelfire.com/me/marmalade/mathtips.html
i used this one for a class presentation!

http://www.pen.k12.va.us/Div/Winchester/jhhs/math/puzzles/mathmagc.html
http://mainland.cctt.org/mathsummer/JosephBond/NumberTricks/numbertricks_std.htm

Here is a whole list of em:
http://mathforum.org/k12/mathtips/beatcalc.html

if ur into magic try:
http://www.wannalearn.com/Academic_Subjects/Mathematics/math_magic.html
http://math.rice.edu/%7Elanius/Lessons/calen.html
http://www.joke-archives.com/quizzes/amazing.html