# Which Poster Doesn’t Belong?

(Cross-posted from Overthinking My Teaching)

Two and a half years ago, I was developing Which One Doesn’t Belong? (before Stenhouse had signed on to publish it). I went on a tour of elementary classrooms to talk with K—5 students all around the Twin Cities about these collections of shapes. I learned a tremendous amount of course, and much of that learning went into the Teacher Guide (which Stenhouse convinced me needed to exist).

I learned a lot, and I also noticed something.

Most of those classrooms had some form of shapes posters on the walls. Triangles, rectangles, squares, and rhombi were proudly and prominently displayed so that students would be surrounded by correct geometry vocabulary. Most of those shapes posters had something important (and unfortunate) in common with the shapes books in the school library and in the children’s homes.

There were rarely squares on the rectangle poster. All of the triangles were oriented with one side parallel to the ground, and most of them were equilateral. Sometimes the shapes had smiley faces. You and I know that a triangle is still a triangle, no matter its orientation. I can assure you not all elementary school children know this. While the vocabulary is good on your standard shapes poster, the math is not. (I decided not to link to examples—you can do your own search and report back if you find my claims exaggerated.)

This summer, Stenhouse is helping all of us to fix this. You can now preorder Which One Doesn’t Belong? shapes posters.

They come as a set of eight, with an insert in the spirit of the Which One Doesn’t Belong? Teacher Guide to help you facilitate student thinking and classroom conversation as they hang in your classroom.

1. Which SQUARE doesn’t belong?

2. Which RECTANGLE doesn’t belong?

3. Which RHOMBUS doesn’t belong?

4. Which HEXAGON doesn’t belong?

5. Which TRIANGLE doesn’t belong?

6. Which POLYGON doesn’t belong?

7. Which SHAPE doesn’t belong?

8. Which CURVE doesn’t belong?

These posters are filled with good mathematics. Consider the triangle poster on top of the pile. The triangle in the lower right is the only right triangle. The one in the upper right is the only equilateral triangle. The one in the upper left is the only isosceles triangle (or is it? do equilateral triangles count as isosceles?) The one in the lower left is the only one you can’t build out of the triangle in the lower right. Students will notice side lengths, angle measures, orientation, composition and decomposition, and more properties of triangles. Some will complain that not all of them are triangles (“too pointy” or “doesn’t have a bottom”). These posters let you and your students sit with—and play with—these ideas over a period of weeks or months.

So as you plan your back-to-school classroom organizing and decoration, I hope you’ll consider making space on your walls for these posters. And I definitely hope you’ll share your students’ ideas here and on Twitter.

Available for pre-order now. They’ll ship in early August.

# A delightful new book on Kickstarter

There are a bunch of people doing really good and interesting work with math and kids these days. Sasha Fradkin is one of these. She has a gift for tapping deep into kids’ mathematical minds and for writing about the beautiful ideas she finds there.

She has written a book—Funville Adventures—that is definitely worth your time and money, and she’s funding its publication on Kickstarter. I have pledged. You should too. I promise you’ll be glad you did.

# National Math Festival

I’m taking Math On-A-Stick and Which One Doesn’t Belong? on the road—to the National Math Festival in Washington, DC on Saturday, April 22, 2017. If you’re nearby, you should come out and say Hi!

I have two Math On-A-Stick sessions—at 10:00 and 4:30—and one Which One Doesn’t Belong? session at 2:30. The Math On-A-Stick sessions are pure play; the Which One Doesn’t Belong? one is interactive but more talky.

There are lots of other amazing folks doing amazing things with all ages, so come spend the day! It’s free. See you there.

# The Summer of Math is back!

We had so much fun the first time around, the Summer of Math is back for a second year, and it has its own webpage!

The basics are the same as last year:

You can head over to The Summer of Math webpage, pay for a subscription, and all summer long (June—August) we’ll ship you awesome, fun stuff that will keep you and your 5—10 year old(s) busy playing and talking math.

You’ll color, count, make patterns, designs and shapes. You’ll read together, draw, and challenge yourselves. You’ll notice. You’ll wonder. You’ll play. And when school starts back up in the fall,

your kids will remember this as the best, mathiest summer ever.

A few small changes include: a new website, three boxes instead of four (but same amount of total mathy goodness, so the net result is higher math-fun density in each box), and a few new things rotated into the lineup (the Truchet tiles are curvy this year!)

Together with a little help from some super smart friends, we’re shooting for a bigger Summer of Math this year, but there is an upper limit on subscriptions. Help us reach it—and as many families as possible—by signing up and by spreading the word.

# Fractivities! Coming soon to a school near you! (If you issue the invitation.)

New to Minnesota, Jennifer Schuetz from the Fractal Foundation brought fun fractal activities, or fractivities, to Math On-A-Stick last summer.
Younger students had the opportunity to learn how the Sierpinski triangle is a fractal – by repeating a simple pattern over and over again, smaller versions of the same pattern are created.
Older students created their own Sierpinski triangles with wooden sticks and glitter glue to make a fractal with sticks!
With help from Minneapolis High School art teacher Stephanie Woldom and math teacher Morgan Fierst, we had tons of fractal fun with hundreds of children and their parents from across Minnesota!
Jennifer’s dream turned into reality: job title of visiting artist/mathematician!

Jennifer leads fractal education in classrooms and other venues across Minnesota, the U.S. and the world (her geographic reach is ever-expanding just like fractals!). Fractals are not only appealing to children but also adults… even senior citizens have fun learning about them!

Instructions to 12 fractivities and associated worksheets and answer keys are at: http://www.fractalfoundation.org/resources/fractivities.

What do you think about projecting videos of fractal zooms accompanied to original music onto the dome of a planetarium? The Fractal Foundation also does this! More information can be found at:  http://fractalfoundation.org/fractal-shows/fulldome-content/

You can also get in touch with Jennifer to see how to do this. Check out some videos at: http://fractalfoundation.org/videos/

Finally, Jennifer is looking for gigs in schools! Get in touch through the Fractal Foundation Facebook page.

# Boxes of Math are here

I and dozens of families across the US, Canada, and England had a blast with the Summer of Math last summer, and now I’m gearing up for the school year version: Boxes of Math.

Starting small with a single option for kindergarten and first grade (five- and six-year-olds, roughly), Boxes of Math will have some overlap with last summer’s Summer of Math, but are targeted at this more narrow age range and the math they’re learning in school.

• A small welcome and introductory shipment before the New Year

• A box for counting and patterning in mid-January

• A box for shape study in late February

• A box for number structures and operations in late March/early April

Each box will have a book, one or more things to get your hands on, and a newsletter with ideas about fun ways to play and to continue the learning in your everyday lives.

## Why Boxes of Math?

Inside these boxes are things that help create conversations. They get children thinking about the most important ideas of elementary math.

A few of the objects that will fill the boxes of math.

Most children who struggle with math later on aren’t familiar with these ideas. They know facts by rote, but not in relation to each other. Or they cannot retain the facts because they see no relationships. They can name triangles, but don’t see all polygons as made out of triangles. They can count large numbers of objects fluently, but they don’t notice whether these objects are arranged in rows and columns.

Those are the things this website is all about.

Struggling or not, all children benefit from exercising their math minds through play and conversation.

Boxes of Math offers children and caregivers opportunities to play, experiment, and talk in ways that bring these ideas to life. Noticing rows and columns is a natural outcome of playing with pattern machines. Playing with 21st Century Pattern Blocks is an extended exercise in putting shapes together and taking them apart.

The target outcome of Boxes of Math is children (and families) with a similar relationship to math as they have to literature. They talk about it, see it in their world, and use it to understand their lives in richer, more beautiful ways than before.