Donald in Mathmagic Land

Enjoy! :)

Twelve Golden Balls

A king got a gift of twelve golden balls

Although all of the balls looked identical, one of these balls was either heavier or lighter than the other balls.

The king was upset and couldn’t figure out which of the twelve balls was different.

He decided that whoever could determine which ball was different and whether it’s heavier or lighter than the other balls in only three trials using a scale, would get the privilege to marry the king’s only daughter.

Thousands of men tried from all over the kingdom. Finally a handsome and clever peasant was able to solve the riddle and proposed to the king’s daughter.

Not only did he become the king’s son in law, but the clever peasant got to keep the twelve golden balls 

Would you like to give it a try?

Photos of us experimenting with the geometry of longsword locks

Videos of longsword dancing:
Ampleforth longsword
Grenoside Longsword
Tiddley Cove Flamborough longsword
Thanks to Vincent for these great photos from Monday's class!

Math Xmas carols!

Here are the lyrics to some of the math Xmas carols I've collected over the years. There are many more available on the internet too!

Math xmas carols

Interesting Puzzle

Appearances can be deceiving!!

Circle geometry on Geometer's Sketchpad/ Geogebra

Here are resources for four guided lessons using this free, dynamic geometry software:

Overview and lesson one (retyped)
Lesson 1 again (scanned version)
Lesson 2 (scanned)
Lesson 3 (scanned)
Lesson 4 (scanned)
Textbook deductive proofs (scanned, somewhat blurry)

You can download Geometer's Sketchpad V. 5 for free at this site: http://www.keypress.com/x24795.xml

and Geogebra at this site:
http://www.geogebra.org/cms/en/download

Which do you like best? Why? I'd be very interested to know!