Check out a GeoGebra animation I just posted: the Pythagorean theorem.It bears much discussion, as students are not likely to spontaneously make out its significance. One way to present it to a class is to first go through the whole thing on a projector, then go back through it slowly, discussing the meaning of each… Continue reading Pythagorean animation
Tag: Technology
Sum of the angles
New animation: Sum of the Angles in a Triangle. This is in the genre of "proofs without words", but of course its pedagogical power comes from students and teacher actually using words to discuss what happens.--Henri
Ripples
Math curriculum ideas expand outward from their originators, like ripples in a pond. In pre-Internet days, it was great to see teachers using photocopies of photocopies of photocopies of worksheets I created, such as "Make These Designs." Nowadays, of course, people can always download and print a fresh copy. One day at an NCTM meeting,… Continue reading Ripples
area of a parallelogram
I posted a GeoGebra animation that suggests the formula for the area of a parallelogram defined by two vectors: <img alt="" height="200" src="data: <img alt="" height="200" src="data:--Henri
The Geometry of the Parabola
Parabolas are a central topic in high school algebra classes, but, perhaps because of the rigid separation between algebra and geometry classes in the US secondary curriculum, we do not usually treat them as geometric objects. While most teachers are aware of some of the parabola's geometric properties, few of us are familiar with the… Continue reading The Geometry of the Parabola
The Common Core
Now that I'm a freelance math education consultant and curriculum developer, I need to pay attention to the Common Core State Standards as they affect everything I do in my professional life. Merely listening to talks about the standards, and reading angry posts about them did not provide a lot of information. On the other… Continue reading The Common Core
A Curriculum Model
The above map is an attempt at a curriculum development model. Traditional pedagogy stays at the top, as it is based on the belief that skills practice and teacher explanations are sufficient to build student understanding. Understanding acquired this way, plus the skills, allow the student to apply the ideas.Would that it were that simple.In… Continue reading A Curriculum Model
Asilomar Report, Part 2
Read about my morning at the Asilomar meeting of the California Math Council here.My afternoon was taken up with function diagrams. First, I attended Martin Flashman's presentation on this topic, then I made my own presentation, and finally I had dinner with Martin. (If you know nothing about function diagrams, read no further. Or find… Continue reading Asilomar Report, Part 2
Summer Workshops
I'll be teaching four workshops in June, at the Urban School of San Francisco's Center for Innovative Teaching. I just posted the info here. Some changes from past years:I've broken up my Geometry workshop, which used to be three or four days, into two chunks, two days each. The first (Hands-On Geometry) will be based… Continue reading Summer Workshops
Asilomar report, Part 1
Once again, I had a great time at the Asilomar conference of the California Math Council. Here are some notes from the first two sessions I attended.Scott Farrand (of Cal State Sacramento) and UC Davis's Rick West's presentation "Diophantine Equations Can Hide Geometric Surprises" was a fun way to start the day.Think of two whole… Continue reading Asilomar report, Part 1
Henri's Math Education Blog 