Hello,
I was wondering if there are any mathematicians on the site who could explain this system. I've tried some web pages but it seems a bit convoluted and I don't understand how this would help someone multiple huge numbers mentally faster. It seems like it would slow things down and that one would lose memory of the last number.
Why would you want to be able to? Order-of-magnitude estimates work pretty well if you're trying to see if your answers make sense, and if you need a gazillion significant figures use a calculator. Just curious, what do you do for a living? Or are you just curious as well? :)
I've heard about people who can do this stuff. Insane. 5 digit numbers squared in a matter of seconds. If you can learn to do it it helps with high level math as well because it has you thinking systematically about numbers and you begin to see patterns and such.
As for the second guy, what's wrong with being curious. I'd personally like to know how to do this. It would make a lot of things easier, plus you could impress your friends. What's not to like?
Make yourself a human calculator with Chisanbop.
malmo wrote:
Make yourself a human calculator with Chisanbop.
I've gotta ask what that is.
Finger math.
Cool.I learned something new on Letsrun. That's a first. Thanks.
http://www.megalink.net/~jones/chisanbop.html
"Briefly, Chisanbop works like an abacus. The fingers on your right hand keep track of the ones, and your left hand keeps track of the tens. Fingers are worth 1 (or 1 group of ten ) and thumbs are worth five (or five groups of ten).
Spread your fingers out above a flat surface. Keep your fingers straight, don't let them curl (it slows you down too much). Fingers that are touching the surface are "activated" and keep track of the numbers. To count to ten, start with your right index finger (one), then the middle finger (two), ring finger (three), pinky (four). To get to five, you simultaneously touch down your thumb and lift all four fingers. That is five. Six is thumb and index finger, seven is thumb and index and middle finger, etc., up to nine.
After nine, you simultaneously touch down your *left* index finger, and lift the fingers on your right hand (ten). The progression for the tens on your left hand is the same as the ones on your right. Index finger is 10, index and middle is 20, index + middle + ring = 30, index + middle + ring + pinky = 40, thumb = 50, thumb + index = 60, etc. The result is a unique representation for all the numbers from 1 to 99.
_The Complete Book of Fingermath_ starts you off with this, then gives you shortcuts, and math problems, and tells you how to use it for somewhat more advanced problems."