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 Shrinky Dinks activity by Rachel Chou, a teacher and department chair at Menlo School in Atherton, CA. I link to it in my Geometry Labs page, as it is very compatible with those activities both in subject matter (Section 10 of the book) and in the hands-on approach.
Tweak: I improved the worksheet on deriving a proof of the quadratic formula based on translating a parabola so its vertex is at the origin. Prerequisites are on my Parabolas and Quadratics page.
Tweak: I improved the worksheet on Graphing Square Roots, which among other things leads to the formal definition of absolute value as a piecewise function.
New-ish: An introduction to the glide reflection, a rigid motion every teacher should know about. (It is an edited concatenation of two blog posts, so it would not be new to regular readers of this blog.)
New-ish: I improved the worksheet on Perspective, and added teacher notes and a GeoGebra applet. It is a good way to introduce inverse variation by way of a real-world lab.
Maybe you can find time this summer to incorporate some of these materials into next year’s classes?
–Henri
PS: some of these updates are part of preparing for my Visual Algebra and No Limits (Algebra 2 / Precalc) workshops, late July in Saint Louis. More info.
Henri's Math Education Blog 