(To search from previous posts on this topic, use the Search box on the right.) I suspect that by far the most common introduction to geometric construction in US classrooms is a presentation by the teacher (or textbook) on various compass and straightedge construction techniques. "This is how you construct a perpendicular bisector. This is… Continue reading More on Geometric Construction

# Tag: MySite

## Errata

According to Merriam-Webster, the word errata means "errors" in Latin, but it is used in English to mean corrigenda which in Latin means "corrections". So there you have it: errors can be corrected — student errors, teacher errors, and (ahem) curriculum developer errors.My books, great as they are, do contain errors. Some are small errors… Continue reading Errata

## Polyarcs

My early forays as a curriculum developer date back to my days as a K-5 math specialist in the 1970's. A key insight of my young self was that activities intended for students were that much more worthwhile if they were also interesting to me. I learned to view with suspicion activities that were boring… Continue reading Polyarcs

## Geoboard Problems for Teachers

At the San Francisco Math Teachers' Circle yesterday (March 4, 2017), we explored four "teacher-level" geoboard problems (All can be adapted for classroom use.) Here is a brief report, including some spoilers, I'm afraid. Pick's Formula It turns out that the area of a geoboard polygon can be figured out by counting the lattice points… Continue reading Geoboard Problems for Teachers

## 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

## Fads and Memes

My defense of eclecticism in teaching generated a strong positive response from teachers, perhaps because I articulated a widely held resentment about the fads that blow through the educational landscape. But interesting questions were raised about what I wrote. In my last post, I tried to clarify my views on math education research. Today, I… Continue reading Fads and Memes

## 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

## Fractions

I have a new Fractions mini-home page, with links to three pages on my site. In this post, I'll use it as an excuse to discuss some general ideas about teaching.Visual RepresentationsIn my Fraction Arithmetic page, I present a visual strategy for figuring out how to add, subtract, and multiply fractions. (There is also a… Continue reading Fractions

## 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

## Visual Algebra

I will be teaching two instances of my Visual Algebra workshop this summer: grades 7-11, June 27-30, in Oakland; and grades 6-9, July 25-27, in Saint Louis. (More info). This is probably the topic I have presented the most often in the last 25 years.To many students, not to mention teachers, parents, and administrators, algebra… Continue reading Visual Algebra