I will offer two workshops this summer (2017), at the Head-Royce School in Oakland, CA. Sign up for either or both! June 26-27: Hands-On Geometry (grades 6-10) June 28-30: Transformational Geometry (grades 8-11) If the times or locations don't work for you, I can offer a workshop for your school or district. Contact me directly.… Continue reading Geometry Boot Camp!
Tag: Geometry
Comparing two approaches
Much can be said in defense of practice exercises, but when all is said and done, very few students develop deep understanding from routine practice. For example, compare these two approaches to the area of a trapezoid. Approach 1The teacher says: ”The area of a trapezoid is given by the formula h(b1+b2)/2, where h is… Continue reading Comparing two approaches
Time and Tide
This is my yearly report on the Asilomar conference of the California Math Council, Northern Section. Because I was presenting three times, I didn't end up attending as many sessions as I would have liked. As always at Asilomar, I enjoyed hanging out with my ex-colleagues, running into friends, and meeting the occasional fan of… Continue reading Time and Tide
Upcoming presentations
I have a bunch of presentations coming up. That will be your last chance to hear me for a while, as my NCTM San Antonio talk was rejected†. Who knows, maybe retirement will finally kick in!Online Webinar: Reaching the Full RangeAs everyone knows, students learn math at different rates. What should we do about it?… Continue reading Upcoming presentations
Big Dodecagon
A classic activity is to cover a 1-inch-side dodecagon with pattern blocks. This provides a great context to discuss symmetry (see Geometry Labs 5.6.) Here is one way to do it:See many others, found by Simon Gregg's students.In the past few days, I've had fun making a double-size, quadruple-area dodecagon: You too, and… Continue reading Big Dodecagon
Eclectic
In between June 27 and August 4, 2016, I presented seven to ten workshops (depending on how you count) ranging from a couple of hours to four days. I share most of the handouts, resources, and slides on my Summer Workshops site. (See below my signature for more details on what's there.)The site will remain… Continue reading Eclectic
Tiling, aka Tessellation
I'm at Twitter Math Camp, which is a teacher-created and teacher-led conference. I had hoped to present a three-part session on Advanced Transformations, but that turned out to be of interest to just one person, so I got to attend "Tessellation Nation", a three-session gathering of people who share an interest in tiling. The session… Continue reading Tiling, aka Tessellation
New(ish) on my Web site
I will probably blog much less during the summer months, given that I am leading many workshops, one after another, with little breathing time in between. I will also probably do little updating of my Web site, so this is a good time to let you know of some recent additions and tweaks.New: An excellent… Continue reading New(ish) on my Web site
Making a Vector in Desmos
A couple of years ago, during a workshop on transformational geometry, a participant objected when I used and recommended GeoGebra and not Desmos. Her main argument was that students love Desmos. Fair enough, but that does not make up for the fact that Desmos is mostly about graphing, while GeoGebra includes the many basic and not-so-basic… Continue reading Making a Vector in Desmos
Animated Demonstrations
New on my Web site:→ Animated slides on the Lab Gear model for signed number arithmetic.Note that for each operation, the model is based on what students already know. For addition, you put down the first number, then the second number, and finally count. For subtraction, you put down the first number, take away the… Continue reading Animated Demonstrations
Henri's Math Education Blog 