# Chisenbop tutorial

## Introduction

Chisenbop is a method of doing basic arithmetic using your fingers. It is attributed to the Korean tradition, but it is probably extremely old, as the soroban and abacus use very similar methods. Probably these other devices were derived from finger counting.

### Counting

The key to finger math is understanding how to count. The right hand stands for the values zero through nine. Each digit counts as one, and the thumb counts as five. Here's an illustration:
 0 1 2 3 4
As you can see, digits 0 through four are pretty self explanatory. The thumb counts as five, so here's how to represent five through nine:
 5 6 7 8 9
The left hand represents multiples of ten, with the left thumb representing 50. Here's how the left hand works:
 0 10 20 30 40 50 60 70 80 90

### Counting practice

Below is a place to practice your counting techniques. You can use it in a number of ways. Press the add 1, add 10, subtract 1, and subtract 10 buttons to see the various combinations. You can also enter in any two-digit value into the text box, hit the tab key, and the fingers will show that combination.
 left (tens) right (ones)
Note that I showed the fingers either fully extended or completely hidden. Usually, finger counting is done against a table or other surface, and the finger is pressed against the surface to indicate it is 'on', or lifted to indicate 'off.' I have chosen this other representation just because it is more clear than looking carefully at pictures to determine if the fingers are touching the surface or not.

## Thoughts on Multiplication

I've recently been thinking about finger-based multiplication. Below is a mini-essay I've been working on in various online forums regarding the topic. Let me know what you think.

mult.html

I have a very exciting new thought about how to do finger multiplication. I've applied to present this technique at TED (Technology, Education and Design.) If my presentation gets accepted, I'll link to it here.

I've noticed a couple of chisenbop Apps available on the iPad. The iPad seems like a perfect tool for practicing this technique. Here's my take on the two choices available right now:

### Chisenbop

This app by design seedling has been available on the app store for some time. It appears to be exactly like the web app on this page. (The authors never contacted me, but that was not necessary.) The one change is moving from my horribly photoshopped finger chopping to nicer finger outlines. There may be more to the app, but I wasn't willing to pay to find out. I find it strange that they charge 99 cents for what appears to be exactly the functionality found for free on this site. It would be fine for a free app, but I'm not sure it's worth paying for. You can get the same functionality (which isn't much) here for free.

### Finger Math

Finger Math, by Our House Interactive is a much more complete offering. It uses a game-like approach to teaching counting and arithmetic skills. It is colorful and inviting, and keeps track of the progress multiple players.

I find this app to be a much better choice for 99 cents. I am impressed enough that I have talked to the author and will be acting as a consultant on future updates.

## EMT App

Here's a note I received from an EMT who uses a variation of Chisenbop to rapidly determine a patient's age

-Andy