Finger counting: Chisenbop
Many of us were probably told off for counting with our fingers as children. But finger counting is a useful way for a child to learn the value of numbers, store intermediate results, and grasp relations between different numbers.
The Koreans have a method called 'Chisenbop' which dates back to the time of the abacus. I'll give one very simple, and fun, example of how it works:
To multiply a number by 9: first place both hands on a flat surface palms down. Choose a number between 1 and 10 to multiply by 9. Starting with the little finger on your left hand, mentally ascribe the values '1' through '10' to each digit of your hand, '10' being the thumb on your right hand. Now, say you chose to multiply 4 by 9. Fold in your left hand's index finger (which is fourth along from left). Count the number of fingers to the left of the folded finger. That is the tens value of your answer. Then count the number of fingers to the right of the folded finger. That is the units value of your answer. 3 fingers to the left, and six (including your left hand's thumb) to the right, give us 36, which is indeed 4 x 9!
Try this with your children. It's a great way to make math and counting fun.
More information on Chisenbop and finger counting methods:
http://klingon.cs.iupui.edu/~aharris/chis/chis.html - Features photos and streaming media explanations. Great resource on finger counting (**** out of 5)
http://www.dnaco.net/~ivanjs/binary.html - Finger counting for binary. Count to 1,023 using only ten fingers! (**** out of 5)
