In preparation for my Asilomar talk, I have updated all my function diagram Java applets to HTML 5.What that means is that (a) you won't get the annoying and scary message warning you of the dangers of Java, (b) the applets will work on a tablet, and (c) you won't need to have GeoGebra installed… Continue reading HTML 5!
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"Enrichment"
During my first ten years as a teacher, I worked in elementary schools. In addition to team teaching my own class (grade 3, then 4, then 5) I was a math specialist for grades K-5. The basic idea was that there was "normal" math (a lot of arithmetic, textbook-based), and there was "enrichment" math. I… Continue reading "Enrichment"
Function Diagrams update
Presentations at AsilomarI will be speaking about function diagrams at the December 7 meeting of the California Math Council (North) in Asilomar. I hope to see some of you there!I first learned about function diagrams at Asilomar, many years ago, from Martin Flashman, a professor at Humboldt State University. Strange coincidence: Martin is also going… Continue reading Function Diagrams update
Unexpected ratio
Triangle ABC is equilateral. MA/ME is the golden ratio! (George Hart showed me this result some time ago.)Vynce Montgomery pointed out that therefore, this could be a way to construct a pentagram. To respond to this challenge, I hid everything but MA and ME, and proceeded from there:--HenriPS: thinking about this a few days later,… Continue reading Unexpected ratio
Crowd-Sourcing
Well, not much of a crowd, because not many people read this blog. Still... I created four worksheets of sorts, each one consisting of a short title and images of a dozen circles. Each circle is divided pizza-like into slices, as in the example above. The four titles: Angles, Fractions, Time, and Percents/Money. Here is… Continue reading Crowd-Sourcing
Parabolas and Quadratics in GeoGebra
I've added several GeoGebra files to my Parabolas and Quadratics page. Some are self-explanatory, others will probably only make sense if you download and familiarize yourself with the accompanying curriculum materials.GeoGebra users may be interested in my use of the very powerful "Sequence" command in creating the trinomial.ggb file. This command allows interactive geometry to… Continue reading Parabolas and Quadratics in GeoGebra
Straightedge and Compass
Back when I was a high school student, I had mixed feelings about compass and straightedge constructions. On the one hand, I liked the geometric challenge, on the other hand, I hated the physical challenge of working with an actual compass. Maybe 20 years later, I had exactly the same experience as a high school… Continue reading Straightedge and Compass
New: GeoGebra files for Function Diagrams
I posted several GeoGebra files for function diagrams:to compare the function diagram of any function with its Cartesian graph.to illustrate the concept of composition of functions.to illustrate the concept of rate of change.to find the parameters of y=mx+b from the position of the function diagram focus.to solve a system of simultaneous linear equations with the… Continue reading New: GeoGebra files for Function Diagrams
Upcoming workshop and presentations
I'll be offering a workshop at East Bay Charter Connect's Third Annual Charter School Symposium on Friday, October 11, in Oakland, CA. My theme is "Connecting the Dots (math on the geoboard and dot paper)". This will include selected topics in algebra and geometry: area, distance, the Pythagorean theorem, simplifying radicals, dilation, slope, and more!… Continue reading Upcoming workshop and presentations
New Transformational Geometry Page
I've added a Transformational Geometry page to my Web site. I expect it will grow over the next year, as I get further into this and develop new ideas and materials. (See also my earlier post on transformational geometry, which generated an interesting response.) --Henri
Henri's Math Education Blog 