Comments on: Arthur Benjamin, The Mathemagician Or Man Calculator

By: Walkin Bathtubs

Walkin Bathtubs — Fri, 30 Jul 2010 18:11:22 +0000

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.

By: San Diego Bch Vacation Rentals

San Diego Bch Vacation Rentals — Thu, 29 Jul 2010 17:04:56 +0000

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.

By: Work from home

Work from home — Mon, 19 Jul 2010 16:49:07 +0000

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: Shipping Broker

Shipping Broker — Sat, 17 Jul 2010 21:03:42 +0000

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.

By: J hass Group

J hass Group — Thu, 08 Jul 2010 16:55:43 +0000

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: Damien Willis

Damien Willis — Thu, 01 Jul 2010 20:36:50 +0000

this guys are amazing