When I Was 13 I Was...

...trying to see the significance of Venn diagrams.

Some 13 yr.-olds (like cool kid Neil Bickford) busy themselves otherwise (perhaps calculating the first 458 million terms of pi....):

http://blog.wolfram.com/2011/09/15/from-pi-to-puzzles/
[link corrected]

Thursday Math Miscellany

1) Sol Lederman's new site for "playing" with Wolfram Mathematica is now up-and-running, and looks gooood! ...but then that would be expected from Sol!!:

http://playingwithmathematica.com/

2) SquareCircleZ blog offers a list of 10 free-for-the-asking help sites for math questions:

http://www.squarecirclez.com/blog/top-10-math-help-sites/5966

3) Finally, Jason Rosenhouse astutely explained Mersenne primes in this recent post:

http://scienceblogs.com/evolutionblog/2011/04/monday_math_mersenne_primes.php#more