A really nice motivational video for teachers. By way of @ghveem on twitter.

## Some GeoGebra examples

25 September , 2009Just thought I should share some good examples of visual mathematics with you.

The first one comes from David Richeson, and pictures what happens when the rays striking a parabola do not come at a straight angle to the vertix.

The second one is from the excellent blog Lessons taught, lessons learnt. It shows some of the statistical capabilities of the new version of GeoGebra.

## Toilet Thoughts on Learning

5 September , 2009I remember once, when attending confirmation training, we were forced (mildly, I should add) to learn the ten commandments by heart. Me being godless already at the age of thirteen, I thought this was a rather meaningless activity, but played along just to please grandparents and others. I digress – the point not being my own attitude towards the ten laws noone is capable of living by, but rather how the priest wanted us to learn them.

Take this cheat sheet with you, and sit in the bathroom, preferably in the toilet.

As absurd as the ten commandments appeared to me, this last statement proved to be much more vital to me. The priest’s words making a deeper impact than any god’s.

And it works. I can’t think of any better quality study time than the lonesome toilet scenario.

There are, of course, a lot of authors who have appreciated the toilet serenity. Even the guys at MAD magazine have their own Bathroom Companion (the turd in the series). Another favorite of mine is the Great American Bathroom Book, or GABB. In three volumes, they gather single-page (single sitting) summaries of all time best selling books.

At work, I have started the secret toilet-exercise-tournament. I print out A4-sized pages with a mathematics problem printed in large lettering on it. PowerPoint is a nice and easy way of making these poster pages. I am thinking of laminating them, in order to… you know, avoid incidents.

The current problem is this one (I think I read this in a lovely little book by Mike Ollerton, perhaps it was 100 ideas for teaching mathematics):

On a 2×2 grid of dots, you can draw one quadrilateral only. The square. How many quadrilaterals can be drawn on a 3×3 grid of dots?

I have so far just started to deploy these sheets on the toilets, so the ideas keep coming. Perhaps the exercises or problems could be more toilet-oriented (“How many sheets of paper…”, “what will the radius of the paper holder be…”, “How big is the proportion of people who prefer the toilet paper end to hang on the inside instead of on the outside” etc…)

To be kind to the toilet-goers, you could consider leaving a stash of post-it notes and a pencil available. Or make a bigger competition out of it; Stick problems on ten toilets in the school, who will be the first one to solve them all…

Suddenly the character “Shitbreak” from American Pie sprung to mind, so perhaps all these toilet exercises will be too weird for a lot of people, I don’t know. Right now it seems like a fun thing to do. If not THE right thing to do.

I will appreciate any suggestions for toilet exercises in the comments. (Pictures are from the flickrCC site). Have a nice weekend!