TED stands for Technology, Entertainment, Design. It started out (in 1984) as a conference bringing together people from those three worlds. Since then its scope has become ever broader. The annual conference now brings together the world’s most fascinating thinkers and doers, who are challenged to give the talk of their lives (in 18 minutes).

Here is one on the more entertaining side, but very fascinating and simply amazing from a Math perspective. In “MatheMagic”, 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. Sit back and enjoy: