Chisanbop: Advanced Counting on Fingers

Date: 3/18/96 at 5:29:34
From: Harbin
Subject: Counting fingers

I saw on TV years ago kids in 1st grade doing advanced math by 
counting on their fingers. They were using their fingers as some 
kind of abacus or something. Does anybody know of this technique, 
and where I can find out more about it? 

Thanks,

Harbin Osteen

Date: 6/24/96 at 20:20:26
From: Doctor Jodi
Subject: Re: Counting fingers

Hi Harbin! 

There's a tutorial by Andy Harris on this method, called chisanbop,
on the Web at:

http://www.cs.iupui.edu/~aharris/chis/chis.html   

Here's more information:

  Chisanbop is an easy, lightning-quick calculator developed by 
   a Korean schoolteacher, Sung Jin Pai. Your grade-school kids 
   can learn to use it in minutes. It requires two hands.

   Try it yourself first. Place your hands palm-down on a table, 
   fingers spread. That's zero. Now make two fists. Your 
   calculator now reads 99, the highest value. Reading from left 
   to right now, each of the four fingers on your left hand 
   equals ten; the left thumb equals fifty; the right thumb 
   equals five; and each of the four fingers on your right hand 
   equals one. Now construct different numbers on your own. 
   Two thumbs folded under could only equal 55; two index 
   fingers, 11.

   Let's try a sample problem: 18 + 26. Show 18 by pressing down 
   the left index finger and the right thumb, index, middle, and 
   ring fingers.

   Now: Think of 26 as 10, 10, 5, and 1. The first two 10s are 
   easy: Press down the middle and ring fingers on your left 
   hands. The 5 is the only tricky part; you exchange between 
   hands. Lift the right thumb (subtracting 5), then press down 
   your left pinky (adding 10, for a net gain of 5). For the 1, 
   press down the right pinky. Your hands now read 44 - the 
   correct answer!
   
And I was browsing the library the other day and found _The 
Complete Book of Fingermath_  by Edwin M. Lieberthal (McGraw-Hill, 
1979), which I recommend.

I hope this helps - please let us know if we can help again.

-Doctor Jodi,  The Math Forum