Henri Picciotto's

November 2023

Hi all,

Since my retirement from the classroom, I have much reduced my attendance at conferences. Still, I usually go to the California Math Council meeting at Asilomar, and this year is no exception. On December I'll be presenting a talk on fractions, for teachers of grades 3-5 (details). I hope someone shows up! (My presentations over the decades have been mostly focused on middle school and high school.)

There may be more conferences in my future, as I try to promote the book I co-authored with Robin Pemantle. We have a contract with a publisher, and we hope the book will be out around September 2024.

This is the 47th issue of this newsletter, and the first one where I link to something that is not about math education. I am a Jew from Lebanon, and thus I obsess about the ever worse news from that part of the world. Here is an op ed which captures some of my emotions in the past few days. Please read the whole thing.

And now, back to math education.

## Blog Posts

Here are links to posts on my Math Education Blog that you might find interesting.
If you are so moved, you may comment on the posts, and/or subscribe to the blog.

### Simplify?

We often ask students to simplify expressions. What is the purpose of this? When is it appropriate? How much is too much? I discuss all this here.

### Factoring Trinomials

Factoring trinomials is another activity that takes up a lot of time in algebra classes. In this post, I present an approach to this topic based on hands-on activities and visual connections.

### Teacher-Created Materials

Teachers don't have a lot of time on their hands, and yet many end up spending some of the time they have creating curricular materials. In this post, I discuss how teacher-created materials fit in the broader universe of math education.

## MathEducation.page

New on my website.

### Recognizing Functions

Functions can be represented in different ways: formula, graph, table. This is a huge part of the secondary school math curriculum, but it can also be an important pedagogical tool. Many years ago, I wrote about the power of activities where students are asked to go from graph to formula: Make These Designs. The technology has changed, but the underlying concepts remain essential.

A few weeks ago, I wrote about asking students to go from data points to formula: Functions from Tables. I added a new directory (Recognizing Functions) where I link to lessons and activities along these lines, including classic labs and a new unit about y = kx^n: n^(th) Power Variation and its Teachers’ Guide.

### Handy Math

This is an introduction to base 5 arithmetic, by Betta and Tom Fisher-York.
Suitable for math clubs and upper elementary school enrichment.

I tweaked and updated:
Applets Directory (links to the interactive GeoGebra pages on the site)
Virtual Grid Paper (the most popular page on my site)
Some Rights Reserved (almost everything on the site is free for non-commercial use)
Directory of Directories (possibly a good entry point to the site?)
Complex Numbers (including games!)
Nothing Works! (my cheerfully titled manifesto from 2005)
My résumé (take a look if you're thinking of hiring me as a consultant)
The Place and Purpose of Puzzles in Math Curriculum
According to Google, these were the most popular pages in the last three months (I am not including the pages mentioned elsewhere in this newsletter):
Virtual Pentominoes (a perennial addictive favorite)
Proving Pick's Formula (why is it so popular? I don't know)
Search (an important feature, given the hugeness of the site)
Function diagrams (yet another representation — a powerful and underused pedagogical tool)
Algebra Manipulatives (comparison and history) and The Lab Gear (the best!)
For a Tool-Rich Pedagogy (some philosophizing, and many links)
Geometry of the Parabola (yes, parabolas are not just algebra!)

## Supertangrams

The supertangram sale is over! The new price is $3 per set, plus$12 for shipping and handling.
Still a bargain!

They come in four colors, so I recommend buying a multiple of four. If you buy four or more sets, you'll get a hard copy of Supertangrams for Beginners Book 2. In any case, you'll have access to dozens of supertangram puzzles, free of charge on my website.

Your students will love them, and so will you!