Math Magic

  Have you ever thought about using the magic of mathematics to help students understand math better and to increase interest?  I hadn't until I read a couple of articles on it.

The mathematical tricks in math can be divided into three categories.

The first type are the ones which place an operation or two on an original number and end up with a given number.  An example is:
Think of a number between  1 and 100.
Multiply your number by 4
Add 12
Multiply this number by 2
Add 16
Divide the number by 8
Subtract your original number.
Your answer is 5.

The second type are those which recombine and rearrange digits. An example is:
Write a three digit number using three different digits.
Mix up the digits so you get a different three digit number.
Subtract the smaller number from the larger number.
Add the digits in the difference to get a one digit number.
Subtract 5 to get the final number.  The answer should be 4.

The third type is where the beginning number is the final number.  An example of this one is:
Write down the year of your birth
Double it.
Add 5
Multiply by 50
Add your age
Add 365
Subtract 615

Your answer should have 6 digits.  The first four are the year of your birth while the last two are your age.  I tried it and it worked beautifully.

The great thing about these tricks and others you can find on the internet and in books, is the fact they can be translated into algebraic equations for each step.  This provides a direct link between algebra and the way these tricks work.

Math magic can helps students learn more about expressions, variables, equal signs, functions, and seeing different types of equations are solved using different algorithms.  If you select the correct magic tricks you can use them to introduce function notation and inverse functions.

In case you wondered, yes, I tried it in all my math classes yesterday and it was absolutely successful.  If I had the stuff, I would have gone in with my magic hat, magic wand, and put on a real show.  The students were amazed at the results.  They laughed and payed attention. They were fully involved.  They want to do it again sometime.  

I got all these magic tricks from this issue of Education World.

Let me know what you think. I'd love to hear.  Have a good day.