I generally prefer my entertainment to be of the frivolous sort. I don’t expect movies to change my life or even move me; I expect a movie to entertain me for 90 minutes. If I sit on the couch with a blanket and a bowl of popcorn it’s not going to be the same if we watch The Last King of Scotland. I read tabloid magazines in the checkout lane and sometimes they jump into my cart. I like fiction. I don’t (generally) read histories or biographies. It’s not that I don’t like learning new things, it’s just that I like to be clear about what I’m getting myself in to.

Last night though, I was simultaneously entertained and educated!

Dr Arthur Benjamin was the after dinner entertainment at my company’s user conference mega-dinner. He did a magic trick and then he wowed us with his mad math skills. He can square any number in his head. Any number. And he told us how he does it!

Let’s say you want to square 17. The nearest *easy* number to multiple is 20. Since you went up 3, you have to go down 3 on the other side. We’re left with 20 (up 3) * 14 (down 3). That’s easy, 2 * 14 = 28, add the zero, 280. But that’s not all, you have to add the square of the number you traveled, in this case 3. 280 + 9 = 289. 17 squared = 289.

Dr Benjamin squared 3, 4 and even a 5 digit number in his head. With the 5 digit number he did it aloud so we could kinda sorta have insight to his thought process. It was very impressive.

It’s also my new party trick. Shhhh, don’t tell. Well, not the 5 digit numbers, I’ll leave those to the professionals. And probably the 4 and 3 digit numbers too. But I can square any 2 digit number now, which is 87 more than I could square without paper before last night. 87 squared is 7569.

2 smart people left their mark:

  1. halimah, 18. April 2008, 3:36

    And I thought reading about all of Henry VIII’s wives was heavy duty. I am impressed. A little spooked maybe, but impressed none-the-less! I’m going to see if The Minion can follow the math logic without backing away from me slowly.

  2. Gary, 22. April 2008, 9:44

    Excellent trick. But you had me at the fact that your company had someone at their user conference who could mid-level mathematics. Quiksilver is lucky to have someone who can speak without using “Like” or “Dude”.