In addition to my blog on WordPress (this site) I maintain a huge **math education site**, featuring articles about teaching math and tons of curricular materials. You should definitely check it out. I keep track of updates to the site on this page.

**Geogebra files**: Many GeoGebra files on my site would not open. Some of them are associated with applets — I fixed those some time ago. I have now fixed the remaining ones. From now on, all the **.ggb** files you download from **MathEducation.page** should open normally.

**Infinity** and **Iterating Functions**: I made some tweaks and fixed some links. The biggest change was to the Infinity Teacher’s Guide.

**Applets:** I restored many GeoGebra files which could not be opened by recent versions of the software. I think I got all of them, but let me know if I missed some!

**Summer Workshop**: This is the page about Hands-On Geometry, my 2020 summer workshop for middle school teachers. It will be hosted by Atrium School near Boston, July 21-23 and Synapse School in Silicon Valley, Aug 4-7.

**Résumé**: updated

**Make your own Pentominoes**: I added a laser cutter file (made by Eben LaPier) to my site. You can download it from my **Geometric Puzzles** page, where I explain why laser-cut pentominoes are preferable to the commercially available ones. The same page, of course, links to lots of puzzles for the classroom.

**Fraction Arithmetic on Grid Paper**: I drastically expanded this page, adding details, graphics, and five homemade videos. One big idea, with many uses across that domain.

**Left or Right?**: I tweaked and linked to this activity which can serve as review or assessment of understanding of *y = mx + b*. Answer without actually graphing: given these two linear functions, do the lines meet to the left or to the right of the y-axis?

**Off and On / Add Till It’s Plaid**: Two lessons that illustrate *ax + by = c* through possibly unfamiliar activities: what does *ax + by* add up to for a generic point (*x,y*) somewhere in the plane? what happens visually when we add or subtract a pair of equations in this form? I used video to present the core of the lessons. I also added an **Off and On applet** so you and your students can conduct that experiment using an equation of your choice.

**Stairs**: This is a beginner’s “rise over run” activity which I designed ages ago for TI calculators. Later, I attempted a Desmos version, which (perhaps due to my lack of expertise) had various issues. I replaced it with a GeoGebra applet, something I knew how to make.

**Number Pyramids**: I added a puzzle-solving and puzzle-creating activity for upper elementary and middle school, mostly based on the addition of whole numbers.

**Doctor Dimension**: I added **Window Shades**, two precalculus lessons by Rachel Chou, inspired by Doctor D.

**Completing the Square**: I fixed the link to a** blog post **outlining how this applet fits in the algebra curriculum.

**Geometry of the Parabola, 2D**: I added a paragraph (by Rachel Chou). Yet another argument to convince the reader that all parabolas have exactly the same shape. They cannot be “pointier” or “wider”.

**Talks**: I added information on the free professional development session **Lessons from Lew**, as well as links to an expanded version of the handouts.

**Iterating Functions**: This page includes interesting materials on this topic, ranging from pre-algebra to precalculus. I added a new lesson by Rachel Chou, about an unexpected application of these ideas to geometry: **Triangles and Iterations**.

**Doctor Dimension**: This is a small unit with big ideas mostly about rate of change, including several GeoGebra applets and a selection of worksheets. It can be used in different ways, in grades 8-12. I added a link to another lesson about piecewise functions.

**Stairs:** This is a Desmos-powered applet that can be used to explore “rise and run”. Unfortunately, it doesn’t work in Chrome on Windows. I added a note to that effect.

**Puzzles in Math Curriculum:**
I combined a couple of blog posts into an article where I break down
what makes a good puzzle, and more specifically, what makes a good
puzzle in math class.

**Function Diagram for y=1/x**: I added a cool-looking static diagram. (If you’re baffled, here’s the **function diagrams home page**.)

**Applets Directory**: I added links to my off-site arithmetic games (**signed numbers**, and **complex numbers**). Programmed in Snap! by Parisa Safa.

**Letters and Postcards: **This is an introduction to linear inequalities and “linear programming.” I added a link to Liz Caffrey’s Desmos Activity Builder version of the lesson.

**Stairs**: I added **a worksheet** to support this Desmos-powered applet about slope and linear functions. (Unfortunately, the applet doesn’t seem to work on Chrome on a PC. I’ll try to fix it, but until I do, try a different browser.)

**Staircases**: I made minor tweaks to this worksheet, which is a great activity about adding up strings of consecutive numbers. It works at all levels from 4th grade, to high school, to math teacher!

**Name That Function!** This is a popular GeoGebra applet where you’re supposed to guess the function by watching an animated **function diagram**. I added links to worksheet versions of it, which can be used instead or in addition to the applet.

**How to Get Some of My Publications:** I removed some out-of-print items. I updated the links to the* Geometry Labs *template and the CircleTrig Geoboard.

**Summer Workshops**: This is the page about my 2019 summer workshop: *Visual Algebra (grades 6-9)*, in two locations: June in Silicon Valley, August near Boston. I added a link to** the part****icipants’ website**. I also added mentions of continuing education / graduate school units, the 75% scholarship for public school teachers, and the free and discounted manipulatives from Didax and Nasco.

I added links to Liz Caffrey’s Desmos versions of **Letters and Postcards** and **Geometry Labs** 9.3 and 9,4. I added a note about Geometry Labs 6.1.

**Symmetric Polygons**: I corrected a mathematical error and expanded the teachers’ notes in this activity for grades 8-10. Co-authored with Lew Douglas.

**Seems Isosceles!**: I added some interactive GeoGebra images to this “teachers’ mathematics” exploration.

** Geometry Labs**: minor tweaks.

**Résumé**: updated.

**SuperTangram Labs**: I replaced an html worksheet which was not really usable with a **downloadable PDF**. (For more information about supertangrams, go to **Geometric Puzzles in the Classroom**.)

**For a Tool-Rich Pedagogy**: This page consists of an argument for the use of manipulative, technological, and paper-pencil tools in math education, followed by a long (but probably incomplete) list of **links** to related pages on my site. I added a link to my popular page about **pattern block** **dodecagons**.

**Pythagorean Theorem home page**: I added an image.

**Geoboard home page**:
I added “Connect the Dots” — lattice puzzles and problems for teachers,
which can also be used in math clubs and in the classroom. (We worked
on those at Math Teachers’ Circles.)

**Summer Workshops**: I set up that page to announce my 2019 summer workshop: *Visual Algebra (grades 6-9)*, in two locations: June in Silicon Valley, August near Boston.

**Soccer Angles**: I added interactive GeoGebra applets to this page, which is an extension of the low-tech Lab with the same name in *Geometry Labs*.

**Spirograph Simulation**:
For some reason, while the online applet worked, the GeoGebra file I
included did not open when downloaded. I got some help on Twitter, and
posted a corrected version.

**Résumé**: updated.

**Math Ed Consulting**: minor tweaks.

**Electronic Graphing**: minor tweaks.

**Errata**: I added a bunch of downloadable corrected pages to the **Lab Gear** books Errata page.

**Front Page**: I added a short intro at the top, and a link to my Twitter page at the bottom. I made similar tweaks to the **About** page.

**Pattern Blocks**: I added a link to Jen Silverman’s GeoGebra pattern blocks applet.

**Site index:** I added links to the games Parisa Safa coded for me in Snap! (Signed Numbers | Complex Numbers)

I created **a conic sections home page****.** (Links to the geometry of the parabola and ellipse, 2D and 3D, and more.)