Fun With Math
This is off-topic but i thought I'd give it a quick mention. My wife recently showed me a site that has weekly math puzzles aimed at different age groups. It has an elementary and middle school challenge as well as two open challenges: one in algebra and one in general math. The latter have no age maximums while the first two do (although having a young age maximum does not make it easy).
Correct answers (which are actually verified by hand - I guess it is good to have cheap student labor) are rewarded by putting you in a drawing for a t-shirt as well as posting your name on the site. They archive the puzzle each week along with the list of people who got the question correct. They also post the percentage of correct entries they get. They have a list of their top-ten hardest where the worst has a correct answer rate of only 18%.
Hope you enjoy the site and I encourage you to give it to your children's teachers to do in school. Too many people find the way math is taught dull and a puzzle with a prize seems a great way to help reverse that.
