03/11/2012
http://www.ted.com/talks/arthur_benjamin_does_mathemagic.html
Arthur Benjamin does "Mathemagic" | Video on TED.com TED Talks In a lively show, mathemagician Arthur Benjamin races a team of calculators to figure out 3-digit squares, solves another massive mental equation and guesses a few birthdays. How does he do it? He’ll tell you.