Transformational Geometry for Teachers: a transformations syllabus for the professional development of teachers and future teachers of high school geometry.
A three-part series on tessellations:
Tiling: Where I argue that tessellation is a worthwhile topic in the math classroom.
Tiling and Transformations: Where I zero in on one particular part of the curriculum.
Tiling in Geogebra: Where guest poster John Golden explains how to “Escherize” a tiling.
Virtual Manipulatives, Part 1: Some philosophizing about learning tools, and an introduction to the Virtual Lab Gear.
And Virtual Manipulatives, Part 2: A discussion of several GeoGebra-based virtual manipulatives, including the Virtual Geoboard , Virtual Grid Paper, Virtual Circle Geoboard, Virtual Tangrams, and Virtual Pentominoes.
Updates to my Math Education Page
I added a new site map: an alphabetical Directory of Directories.
New Applets: I used GeoGebra to make new applets — Virtual Geoboard, Virtual Circle Geoboard, Virtual Grid Paper, Virtual Pentominoes, Virtual Tangrams, and Symmetry with Pattern Blocks. Also Google Drive for Virtual Lab Gear and Virtual Tiles. In each case, my goal was to offer useful features to compensate for the loss of immediacy of physical materials.
Symmetry: I created a home page for this topic, including links to existing materials, to photos of student-created designs, to a unit for elementary school, and to Symmetry Labs, a new online unit for middle school and high school.
What else is new
11-12 Mar 2021 (4pm to 4pm Pacific Time): I will participate in the Julia Robinson Math Festival’s Math Buffet, an international 24-hour online event for kids (and adults).
9 Feb 2021: Math Teachers’ Circle: Tangrams and Pentominoes are geometric puzzles which are fun and interesting for all ages. Can students use these manipulatives in an age of remote instruction? Yes! In this workshop, I shared virtual tools I created to make that possible. I proposed problems suitable for ages 9-99, and participants worked as a team to generate dozens of solutions. The activities touched on symmetry, area, congruence, and similarity.
27 November 2018: I moved my blog into WordPress (here.) I thought the move had happened smoothly, but some graphics, and some entire posts, failed to materialize. Also, many links are broken. If you come across these problems, please notify me, indicating which post had the issue. Thanks!
I have retired from the classroom after 42 years as a math teacher in K-12 — from counting to calculus. I now work with teachers and schools:
Math Education Consulting
On this page: announcements about new material, updates, etc. on the site; new publications; my appearances at conferences; and my other activities in math education.
Note: All material on this site is copyrighted. You may reproduce it for any non-commercial purpose, as long as you credit me and link to the blog. More info.
(I am also involved in word puzzles, especially cryptic crosswords.
More on this.)