and last night flipping through Henry Segerman’s math and 3d printing book I found these bubble project ideas:

So I printed two of Segerman’s shapes overnight and tried out a new bubble project this morning.

I started with some simple shapes from our old bubble projects – what happens when you dip a cube frame in bubbles?

The next shape we tried was a tetrahedron frame:

Now we moved on to two of Segerman’s shapes. These shapes are new to the boys and they have not previously seen what bubbles will form when the shapes are dipped in bubble solution.

If you enjoy listening to kids talk about math ideas, their guesses and descriptions of the shape are really fun:

The second shape from Segerman we tried was the two connected circles. We actually got (I think) a different shape than I’d seen in Segerman’s video above which was fun, and the boys were pretty surprised by how many different bubble shapes this wire frame produced:

Definitely a fun project. I tried a bubble project for “Family Math night” with 2nd graders at my younger son’s elementary school last year. Kids definitely love seeing the shapes (and popping the bubbles).

Anyway, I ran out to home depot and got some wire and we made some knots. I had each of the boys make a trefoil knot and then make a random knot of their own choosing. In retrospect I wish I’d spent maybe just 5 minutes explaining some of the ideas in Richeson’s blog post – oh well, the excitement got the better of me 🙂

Here’s my older son playing with his trefoil knot and making a Mobius strip bubble. I love the “hey, I actually think I got it” moment:

Here’s him playing with the knot me made – in retrospect I’d argue for a knot that was slightly less complicated:

Next up was my younger son. First up was the trefoil knot and we got another great moment “I think this might be a Mobius strip” !!

Finally we made his own knot and explored. Again, I’d probably ask for a less complicated knot if I was doing this again:

So, that so much to Dave Richeson for posting his old project – this is an incredible project, and an especially great one for kids. The appearance of the Mobius strip is really quite an amazing little math miracle!

At the end of the project with my younger son this morning he remembered that we’d see some of the 4 dimensional shapes we were looking at in our Zome Bubble project. He went on to wonder if we dipped our 4 dimensional shapes in the bubble solution would we get a 5 dimensional shape. Well – We had to try that!

First, though, we looked at what happened when you dipped a cube and tetrahedron in bubble solution:

Next we tried the 4 dimensional shapes – what happens when you dip the zome versions of the 5-cell and the Hypercube into the bubble solution?

Ahead of the dipping, my younger son had this thought:

“I think we are going to see a 5 dimensional shape”

Here’s what happened:

I’m really loving just playing around with the 4 dimensional shapes with the boys. Soon we’ll move on to looking at the 4d version of Patrick Honner’s Pi Day project – can’t wait for that!

Finally, here’s the project from this morning that led to my younger son wondering about bubbles:

Saw an interesting tweet last week and I’ve been thinking about pretty much constantly for the last few days:

Ok #MTBoS and #iteachmath tweeps! If you were asked to plan a 4 day math themed summer camp for rising 6th graders, what would you dream up?? You have 80 mins a day and no more than 20 kids. Go!!

I had a few thoughts initially – which I’ll repeat in this post – but I’ve had a bunch of others since. Below I’ll share 10 ideas that require very few materials – say scissors, paper, and maybe snap cubes – and then 5 more that require a but more – things like a computer or a Zometool set.

The first 4 are the ones I shared in response to the original tweet:

(1) Fawn Nguyen’s take on the picture frame problem

This is one of the most absolutely brilliant math projects for kids that I’ve ever seen:

(3) Martin Gardner’s hexapawn “machine learning” exercise

For this exercise the students will play a simple game called “hexapawn” and a machine consisting of beads in boxes will “learn” to beat them. It is a super fun game and somewhat amazing that an introductory machine learning exercise could have been designed so long ago!

In the essay he uses the game “checker stacks” to help explain / illustrate the surreal numbers. That essay got me thinking about how to share the surreal numbers with kids. We explored the surreal numbers in 4 different projects and I used the game for an hour long activity with 4th and 5th graders at Family Math night at my son’s elementary school.

This project takes a little bit of prep work just to make sure you understand the game, but it is all worth it when you see the kids arguing about checker stacks with value “infinity” and “infinity plus 1” 🙂

Here is a summary blog post linking to all of our surreal number projects:

I learned about this problem when I attended a public lecture Larry Guth gave at MIT. Here’s my initial introduction of the problem to my kids:

I’ve used this project with a large group of kids a few times (once with 2nd and 3rd graders and it caused us to run 10 min long because they wouldn’t stop arguing about the problem!). It is really fun to watch them learn about the problem on a 3×3 grid and then see if they can prove the result. Then you move to a 4×4 grid, and then a 5×5 and, well, that’s probably enough for 80 min 🙂

This is a famous problem, that equally famously generates incredibly strong opinions from anyone thinking about it. These days I only discuss the problem in larger group settings to try to avoid arguments.

Here’s the problem:

There are prizes behind each of 3 doors. 1 door hides a good prize and 2 of the doors hide consolation prizes. You select a door at random. After that selection one of the doors that you didn’t select will be opened to reveal a consolation prize. At that point you will be given the opportunity to switch your initial selection to the door that was not opened. The question is -> does switching increase, decrease, or leave your chance of winning unchanged?

One fun idea I tried with the boys was exploring the problem using clear glasses to “hide” the prizes, so that they could see the difference between the switching strategy and the non-switching strategy:

(10) Using the educational material from Moon Duchin’s math and gerrymandering conference with kids

Moon Duchin has spent the last few years working to educate large groups of people – mathematicians, politicians, lawyers, and more – about math and gerrymandering. . Some of the ideas in the educational materials the math and gerrymandering group has created are accessible to 6th graders.

Here’s our project using these math and gerrymandering educational materials:

(11) This is a computer activity -> Intro machine learning with Google’s Tensorflow playground.

This might be a nice companion project to go along with the Martin Gardner project above. This is how I introduced the boys to the Tensorflow Playground site (other important ideas came ahead of this video, so it doesn’t stand alone):

— John Allen Paulos (@JohnAllenPaulos) June 15, 2016

You don’t need a computer to do this project, but you do need a way to pick 64 random numbers. Having a little computer help will make it easier to repeat the project a few times (or have more than one group work with different numbers).

For this project you need bubble solution and some way to make wire frames. We’ve had a lot of success making the frames from our Zometool set, but if you click through the bubble projects we’ve done, you’ll see some wire frames with actual wires.

Here’s an example of how one of these bubble projects goes:

And here’s a listing of a bunch of bubble projects we’ve done:

Yesterday I was able to watch the Global Math Project presentations (well, most of them) via the Facebook Live feed. Hopefully those videos will be preserved here:

One tank that caught my eye was given by Henry Segerman. I’d guess that his work and Laura Taalman’s work account for at least 80% of what I know about exploring math through 3d printing.

As I write this post there are 96 prior posts with the “3D Printing” tag on my blog. 3D Printing is still pretty new, and I think many people around math are only starting to see its use in education. Segerman’s talk made me want to throw together a list of fun projects that we’ve done just in case anyone is looking for a starting point after seeing his talk.

Some of my original thoughts on exploring math through 3d printing can be found in this blog post from March 2014 which features two really neat videos from Brooklyn Tech and Laura Taalman:

(1) James Tanton’s Geometry Problem and 3d printing

Since this blog post was inspired by a talk a James Tanton’s Global Math Project, it seems appropriate to kick it off with a project inspired by Tanton:

What is surface area of figure formed by all points within a distance 1 from a regular tetrahedron with faces of area 1?

(2) Hard to highlight just one project that Segerman Inspired, so here’s the first of 2

One of the Segerman’s examples in yesterday’s talk was about bubbles. He showed a few complicated bubble examples but there are simple ones that are amazing, too. Here’s an example showing that the “bubble” formed by dipping a tetrahedron in soap is the same shape as a 4-dimensional shape:

(6) Exploring connections between algebra and geometry

3d printing can come in handy for looking at math ideas that previously you could only study on paper or on the computer screen. For example, a common algebra mistake is to think that:

Here’s what these two surfaces look like:

Here’s two projects exploring these algebra ideas with the boys:

(8) 3d printing can be a fun way to review ideas from elementary geometry

In his talk yesterday Segerman mentioned a few prints that his undergraduate students created. As he showed this projects he talked about how the creation process really helps students understand and explore the underlying math.

In the project below, creating the shape of the tile helped me review and explore equations of lines with the boys:

After getting some intuition from this problem we extended the problem to 4 dimensions using Taleb’s approach. The prints were really fun to play with and it is amazing to hear kids talk about these shapes that come from 4 dimensions:

But 3d printing can help you see even more advanced ideas. Here’s a cube inside of a dodecahedron, for example:

and, of course, many (most!) of examples that Henry Segerman showed in his talk yesterday are perfect for showing how 3d printing can help everyone experience some advanced ideas in mathematics.

I’ll end with the project we did yesterday, which is a delightful example of how 3d printing can help you explore a math idea:

Yesterday I learned that Mathematica has a wide variety of knots that you can 3d print. We’ve done a few knot projects in the past. Here are 3 of them:

I thought that actually being able to hold the printed versions of so many different knots in your hand was going to be a game changer for knot projects, though. So, I printed a few as test cases and had the boys look at them.

My older son went first:

My younger son went next – he had a couple of things to say, but wanted to point out some of the knots in Colin Adams’s book, so we cut this video a little short so that we could go find the book:

After finding the book we were trying to match one of the printed knots with the knot in the book that he had wanted to print. The knot he wanted to print had 8 crossings and the one that we thought matched it turned out to have 7. Whoops – we had the wrong knot 🙂 A good accidental lesson that comparing two knots isn’t super easy!

I’m really looking forward to trying more projects with these prints. There are a little over 30 different knots with 8 or fewer crossings. It’ll probably take a week to print them all, but that’ll be a fun collection to have for future knot projects!

I have 30 min for the 3 projects with the kindergartners and an hour with the 1st graders, so I think for the younger kids we’ll just do one coloring sheet. The sheets I’m going to use come from an old post from Richard Green discussing a really neat result about tiling octagons. The result is a pretty deep result from geometry, but with the side benefit of hopefully producing images that young kids will enjoy seeing and coloring with 4 colors. I learned about Green’s post from Patrick Honner about 2 years ago:

Here are the two images octagon tilings I’ll use in the project.

Next we’ll move on to making bubble shapes with our Zometool set. As I write this, at least, I think I’ll dip the shapes in the bubbles myself. I’m worried that letting a room full of younger kids loose on a container full of bubble solution will end up with bubble solution everywhere. Also the zome parts are small and I won’t be able to supervise all of the kids on my own. Anyway, we’ve done a few zome bubble projects and my kids and the neighborhood kids have really enjoyed them. The shapes are really incredible to see and trying to guess what the bubble shapes will look like is a fun challenge for kids. Here are a couple of our old zome bubble projects:

Finally, with the kindergartners I’m going to do the paper folding project that we did for our original Family Math. I did the same project with the kindergartners last year and it went reasonably well (assuming that you set your expectations on the “me dealing with 30 6 year olds” setting!). I’ve got the first graders in a week, so I’ve got a bit of time to think through a replacement project to avoid duplicating last year’s work. Here’s the project as we did it in 2011:

I’m sick and not working today but instead have been sort of day dreaming about all of the math the boys and I worked on this year. The sheer amount of absolutely great ideas that people are sharing via blogs, twitter, or otherwise makes it incredibly easy to find fun projects. Here are some of my memories from 2016.

Again, though, I’m sorry that this likely reads so poorly. Despite being so sick it was fun to write this and think back through the year.

(1) Sharing math that I saw from professional mathematicians

Two of my favorites in this category came from Bjorn Poonen, Eugenia Cheng and Laura Taalman:

The project we did after seeing Poonen’s problem about n-dimensional spheres was the most viewed math project for kids on my blog this year:

At the risk of failing to mention lots of people in my current Dayquil-induced state, I’m also incredibly grateful to these professional mathematians who have inspired tons of our projects with the math they’ve shared:

and one of the neatest things that happened to me all year was when Joel David Hamkins created an amazing “fold and punch” activity based on an activity that I found in some old material from “Family Math Night” at my younger son’s school:

Here are all of our project inspired by Tanton – you can basically pick one at random and have an amazing math conversation with kids (though if you don’t want to pick at random the candy dividing one is really cool!):

(3) Laura Taalman and Henry Segerman’s work in 3d printing

The work that Taalman and Segerman are doing with math and 3d printing is stunning. I mentioned one of projects inspired by Taalman above – there are dozens’s more:

Segerman published a new book about math and 3d printing this year. I was incredibly lucky to be able to bring the boys to a talk he gave about his work:

(4) Sharing new and / or popular math ideas with kids.

Erica Klarreich and Natalie Wolchover are doing amazing science (and especially math!) journalism work at Quanta Magazine. Oh to have had writing like theirs around when I was a kid!

I don’t think it is possible to overstate the importance of Klarreich’s and Wolchover’s writing. They are going to influence a generation of young mathematicians and physicists.

Another fun math-related item that got a lot of attention this year was Sugihara’s “ambiguous cylinder”:

We really had fun playing with this shape and I want to give a special thanks to Dave Richeson and Brenda Landis for sharing a 3d print of the shape.

(5) The sphere packing problem reminded me of the new PBS Infinite Series work that Kelsey Houston-Edwards is doing.

Holy cow are these videos amazing! Here’s just one example:

Wwe are one behind because of the holidays, but each of Houston-Edwards’s videos has inspired a really fun project. Her videos are great tools to use to share math with kids.

There are actually a couple of projects that Simon Gregg’s tweet inspired. The main picture is this one (which always has weird embedding problems, so sorry it isn’t aligned correctly):

Prepping for this project to make sure that we could do it with our Zometool set was really fun, too:

This was a great project with the boys and I also used it for a talk to a high school math camp at Williams. If you play with the Desmos program below your mind will be blow, too 🙂

I know there are lots of ways to spend money on math-related games, books, and toys in general. Building up a good Zometool set is my #1 recommendation. The opportunities to play and learn and study are endless!

This terrific project inspired me to try it out in 4 dimensions. That led to a fun multi-day project with my older son as we search for which 4-dimensional platonic solid was the most spherical (according to Honner’s definition).

This project combined ideas from geometry, Zometool, and 3D printing.

Honner’s “pi day” exercise is a perfect example of why I love all of the sharing of math ideas that people are doing these days. Not in a million years would I have come up with an idea like that – luckily he did, though, and it turned out to be a really fun way to explore more than just 3d objects!

It really was a great year in math for us. Can’t wait to see what 2017 brings.

Last night we printed a shape from Henry Segerman’s new 3d printing book Visualizing Mathematics with 3D Printing:. We’ve done many project based on Segerman’s work and even were lucky enough to be able to attend his talk at MIT earlier this fall:

The shape we printed last night is Henry’s 3d representation of the 5-cell – a 4 dimensional “platonic solid” ( You can read more about the shape here: The Wikipedia page for the 5-cell)

If you search “Segerman” in the blog you’ll find more than 10 projects we’ve done based on his work!

I started off the project today by asking my younger son for some thoughts on the 5-cell:

One interesting thing that he remembered is that he’d seen the shape previously in some of our bubble projects, so we brought out the bubble solution to make the shape out of bubbles. It was really interesting to hear how he viewed the two shapes differently.

Sorry for the absolutely awful camera work in this video – you’d think I’d have gotten the hang of this after 4,000 videos . . . . .