Math Ed Page Updates

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.

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 participants’ 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.)