28 May 2020: I restored a post (Symmetry in Spain). Math-relevant photos, and links to photos, from a vacation in 2013.
10 February 2020: I sent out my e-newsletter. Topics included guided inquiry, conic sections, a polyomino puzzle, a grid approach to fractions, graphing ax+by=c, and number pyramids. Also: an announcement of my summer workshop — Hands-On Geometry on both coasts. Alas, there was a wrong date for the latter, and a couple of broken links. It’s all fixed online!
4 February 2020: Infinity is a mind-bending topic that everyone finds interesting. I shared infinity paradoxes, puzzles, problems, and proofs from a high school course I developed at the Berkeley Math Teachers’ Circle.
7 December 2019: At the Asilomar conference, Kim Seashore and I presented Lessons from Lew. (Kinesthetic angles, Golden Ratio, Symmetric Polygons.) Later, I presented Connect the Dots, an extravaganza of geoboard / dot paper activities for ages 9 to 99: curricular challenges, interesting puzzles, and some unsolved problems.
26 November 2019: I restored the graphics in my post Completing the Square.
30 October: I sent out my e-newsletter. The main topics were test retakes and a response to Freakonomics Radio episode about math education. I also highlighted recent contributions to my blog and website by Rachel Chou.
5 October 2019: Along with Kim Seashore, I was a presenter at Lessons from Lew, a free professional development session. We shared Lew Douglas’s lessons on angles, the golden ratio, symmetric polygons, and more. Links to an expanded version of the handouts, here.
12 September 2019: I restored the graphics in my post Add Till It’s Plaid, wherein I share a great lesson on solving systems of linear equations.
10 September 2019: I restored the graphics in my post Making a Vector in Desmos.
23 August 2019: I sent out my e-newsletter. The main topics were: “Taking Notes vs. Doing Math”; a review of a book that was a big influence on my teaching; the place of puzzles in math education. Plus a lot more. Subscribe!
17 August 2019: An entire post (about Doctor Dimension, the flat scientist) was missing. I restored it.
5 July 2019: I fixed more broken links, this time in a series of posts in which I challenge the dogmatic stance of teachers who are overly stingy about offering hints to students who are stuck: About Hints, About Hints, the sequel, and Hints! The topic that will not die.
1 July 2019: I fixed broken links to I’ve Got a Problem!, the first of two posts about a time where I was in the student’s shoes, and I learned a lot from it.
18 June 2019: I restored the figure in Geometric Series, a blog post about a geometric way to visualize the case where the common ratio is less than 1.
18 April 2019: I
restored the graphics and repaired the links in my 2011 notes from a
meeting of Escape from the Textbook! a grassroots math teacher group
that met for a few years in the Bay Area.
(Part 1: tools, backward design | Part 2: Miras | Part 3: habits of mind)
12 April 2019: I restored the graphics in the Partitions post.
3 April 2019: I restored the graphics in the Egyptian Fractions post.
15 March 2019: I sent my e-newsletter out. The main topics were story tables, an argument against the shrinking of geometry, a book review, geoboards + related topics, and the announcement of my summer workshops. Subscribe!
20 February 2019: I restored a missing equation from Pruning the Curriculum, a 2015 blog post where I suggested teaching fewer topics in more ways. I also fixed a link to the related Mapping Out a Course.
5 February 2019, 5pm: Geoboard Puzzles and Problems. I led the East Bay Math Teachers’ Circle at Berkeley High. The geoboard is a great learning environment, but in this session we used it as an arena for puzzles and problems, some of them unsolved, involving diagonals, triangles, non-triangles, and zigzags! You can download the handout.
9 January 2019: I will offer a grades 6-9 version of my workshop on Visual Algebra twice this summer: June 25-27 at Synapse School in Silicon Valley, and again August 7-9 at Atrium School near Boston. More information.
9 January 2019: I restored the graphics in two posts: “A New Algebra” where I bragged about Robert Davis’s praise for my approach; and Geoboards and Dot Paper, where I introduced subsequent posts on using these tools as a microworld for problem solving, and bragged about having invented the “tilted squares” intro to the Pythagorean theorem decades ago.
8 January 2019: I restored the post Themed Courses?, where I discuss the question of whether courses with a theme are preferable to “hodgepodge” courses, whose topics range widely.
28 December 2018: I restored the illustration in the “Enrichment” post.
22 December 2018: I restored the Math for Equity post, where I reviewed an excellent book about “Railside” school, where teachers developed tremendously effective approaches to teaching untracked classes in a “wrong side of the tracks” school. Their work was studied by math education researchers at both Stanford and Berkeley.
22 December 2018: I restored the “themes, tools, concepts” map in the Proportional Relationships post. That diagram was the main point of the post, so I feel bad that a few dozen visitors to the page didn’t get to see it.
22 December 2018: I restored the Time and Tide post, where I link to and discuss my three (!) presentations at Asilomar (2016), and propose some strategies to slow things down in classroom discussion.
21 December 2018: I restored the graphics in the Algebra Manipulatives post, where I compare the Lab Gear with other models, and reply to a correspondent. Also the illustration in Straightedge and Compass.
17 December 2018: I restored the Geoboard Problems for Teachers post. Surprisingly to me, this was one of my most visited post ever.
15 December 2018: I restored my Polyarcs post, which had not survived the move to WordPress. Interesting discussion in the comments!
14 December 2018: I found the graphics from my Stumped by Euclidea blog post on the Internet Archive’s Wayback Machine! It was a bit of work to put them back into the post, but not as much work as recreating them! I’ll continue to work my way back through the posts to restore content lost in the move from Blogger.
1 December 2018: I attended the California Math Council Northern Section meeting in Asilomar. My presentation was about Reaching the Full Range of students in a heterogeneous class (i.e. any class). I put lots of links about this on my Talks page.
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!