Guilloché Pattern Generator

Anyone who ever enjoyed playing with the Spirograph will enjoy the Guilloche Pattern Generator.

Definitions of Terms Commonly Used in Math

Continuing in the theme of finding funny math stuff on the Web, I give a partial list of definitions from In Between Meals. The see the rest of the list, visit the sight.

CLEARLY: I don't want to write down all the in-between steps.

TRIVIAL: If I have to show you how to do this, you're in the wrong class.

OBVIOUSLY: I hope you weren't sleeping when we discussed this earlier, because I refuse to repeat it.

RECALL: I shouldn't have to tell you this, but for those of you who erase your memory tapes after every test, here it is again.

WITHOUT LOSS OF GENERALITY: I'm not about to do all the possible cases, so I'll do one and let you figure out the rest.

ONE MAY SHOW: One did, his name was Gauss.

Interesting Websites About Pennies

This website discusses size (number, area, weight, dollar amount) in terms of pennies. It is a great site for kids to help understand how big is big. The Mega Penny Project

This sight, as an aside, has a section on coin stacking. It is fascinating to see what people do with their time.

Lego Kit - The Penrose Triangle

I found this on Stumble!

How Did You Remember How to Tell Your Right From Your Left?

I recently asked a six-year-old how she remembered right from left. She told me that she just "used her brain and thought about it". So, I asked her how she learned it. She told me that her mother told her one day when she was brushing her hair and then she just remembered. She doesn't use any special technique to remember. She just knows.

What does this have to do with math? Not much except... The way that I learned my right from my left is similar to the definition of "even" and "odd".

The definition of even: Divisible by two.
The definition of odd: Not even.

I remembered which was my right hand because it was the one that I used to write with. My left hand therefore was the one that wasn't right.

The only flaw: I was ambidextrous and could never remember the hand I supposed to use (my mom and the kindergarten teacher had rules about such things).

How did you remember? Take the poll in the left column.