Comments on: Arthur Benjamin, The Mathemagician Or Man Calculator

By: Mark

Mark — Thu, 26 Nov 2009 22:08:31 +0000

I'm chuffed that I figured out the “tell me six digits and I'll tell you the seventh” trick. For this to work, he needs one of the random two-digit numbers that he gets given to square to be divisible by three – roughly 80% likely given four random numbers, and if it didn't happen, he'd either drop the trick or come up with another way to get the number he wanted. That would make the square divisible by nine, and he simply uses the “sum of digits is also divisible by nine” trick. Not sure how he would handle the 20% likely situation where the result could be 0 or 9 – maybe there's another level to this I haven't appreciated yet.

The rest is just crazy, though. I can get my head around memorizing all two-digit squares, and may even be able to do it with practice, but the four-and five-digit stuff blew me away.

By: pligg.com

pligg.com — Tue, 17 Nov 2009 13:27:51 +0000

Arthur Benjamin, The Mathemagician Or Man Calculator…

nerdmodo.com — The man calls himself a mathemagician and can do 5 digit squares faster than you can type it in a calculator. (Submitted by hellengineer)…

By: e cigarette

e cigarette — Thu, 12 Nov 2009 03:06:22 +0000

Awesome! This guy is simply amazing.

By: gary

gary — Wed, 11 Nov 2009 19:14:00 +0000

This is old as dirt guys..

By: Umar Farooq Zia

Umar Farooq Zia — Tue, 10 Nov 2009 23:45:43 +0000

I think they probably have and he's also written a book about mind math, so I guess he'll be open to the idea.

By: nanoloupe

nanoloupe — Tue, 10 Nov 2009 23:34:59 +0000

I was wondering just the other day if anyone was doing fMRI on any of these guys with built-in lightning calculators. Does anybody know him well enough to ask if his skill has been studied with functional neurological scans? Is it raw speed in standard patterns, or does he use unusual neural pathways possibly augmented by increased signal patterns more often associated with memory?