The Aperiodical 

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Martin Gardner celebration week in Nottingham

By Peter Rowlett. Posted October 29, 2012

Last Sunday saw the anniversary of the birth of Martin Gardner, and as a celebration, the Gathering for Gardner people planned a world-wide party ‘G4G Celebration of Mind‘. It happened to be Maths Jam night on Tuesday, so we put the Nottingham Maths Jam on the G4G-COM map. Then on Friday three of us had agreed to take a puzzles stall to the Nottingham STEM Pop Up Shop, so I added this to the map as well.

A Celebration of Mind party is supposed to “celebrate the legacy of Martin Gardner on or around Sunday, October 21, 2012 through the enjoyment of [one or more of] Puzzles, Magic, Recreational Math, Lewis Carroll, Skepticism and Rationality”.

At Maths Jam I printed a bunch of flexagon material from the Flexagon Party page. I also had a plan: having finished two jobs in recent years with piles of business cards outstanding, I brought these to try some business card origami. In fact, we decided to make a business card Menger sponge. So we started folding.

Business card folding begins

Meanwhile, John Read had come equipped with some colourful designs to make hexahexaflexagons.

John Read’s first hexahexaflexagon of the evening. Designs from flexagon.net.

John Read’s second hexahexaflexagon. Designs from flexagon.net.

At the same time, Jon made a trihexagon.

Trying to make a triflexagon

Finally, after much business card folding,we had a Menger sponge* (*not a real one, it being a fractal after all!). Here it is, in Maths Jam-style, balanced on a pint of beer.

The completed business card Menger sponge

And here’s a shot through the Menger sponge, where a geometry puzzle is being attempted.

Through the completed business card Menger sponge, some geometry is happening

Here are a couple of the other puzzles that we tried, some from the #MathsJam tag on Twitter:

You have 100 coins, 10 of which are showing heads and 90 of which are showing tails (though these are indistinguishable by touch). Blindfolded, you must divide the coins into an even number of heads and tails. 

Which is bigger, 3^(21!) or 2^(31!)?

Then on Friday we made our way to Broadmarsh shopping centre for our afternoon at Nottingham’s STEM Pop Up Shop.

Nottingham STEM Pop Up Shop welcome notice

Here’s a picture of our stall, with Kathryn Taylor presiding, and in the foreground the posters about Martin Gardner, mathematical games and mathematicians that I had printed. Someone did ask me who Martin was and I explained a little; I think I also convinced him to come to Robin Wilson’s talk on Lewis Carroll next month in Derby.

Martin Gardner posters on our stall

Here’s the detail of our stall, which we called ‘Solving it like a mathematician’. You can get details of the set of puzzles on my website.

The STEM Pop Up Shop ‘Solving it like a mathematician’ stall

Looking around the shop, I requisitioned the Alan Turing postcards from the ‘My Favourite Scientist’ set for our stall!

Alan Turing postcards

Here’s a wider view of the stall, with Kathryn entertaining a customer.

Kathryn Taylor at our stall

And finally, here’s John Read bewitching a crowd with the loop on a chain trick.

John Read enthuses a crowd with a ring on a chain

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Maths at the East Midlands Big Bang Fair

By Peter Rowlett. Posted June 29, 2011

Recently I was invited to take a mathematical puzzles stall to the East Midlands Big Bang science fair. This took place in Nottingham yesterday. I gathered a few friends from the Nottingham MathsJam group, which I run, and we planned what we could do with a stall. We agreed a list of puzzles we could put together and run. We felt it was important to have solid, physical puzzles and games that would attract people to the stall, including making use of the floor area, as well as more advanced and intriguing items and a takeaway sheet. I wanted the takeaway sheet to provide some advice on problem solving techniques as well as some puzzles to try. There were various extra constraints as well as what we could physically make with no budget, including the difficulty of catering to the wide age range of those attending: 9 to 19!

We met a couple of weekends ago and agreed a set of puzzles, tried them on fellow MathsJammers at the monthly meeting last week and have spent the last week or so making bits and pieces ready for the fair yesterday (particular thanks in that regard are due to John Read and Kathryn Taylor). We called the stall “Solving it like a mathematician”. For big, attractive, fun we had Latin squares with giant playing cards, a puzzle involving arranging tokens inside a giant circle (a hula hoop) and matchstick puzzles with giant matchsticks (bamboo canes). For hands on activity we were making Möbius strips. The more in depth tabletop exercises included: Buffon’s needle for estimating pi (we got 3.78 from 141 throws); a ‘wisdom of crowds’ guessing how much rice is in the jar and rice on the chessboard exponential growth combo; and, the fifteen puzzle and how to tell if an arbitrary position can be solved. Each puzzle had an advice sheet and these as well as the handout are available on a page on my website.

I have been unwell recently so I took a lighter load than I might have for the day. I helped set up the stall and stayed for the first hour, in which not much was happening, then left until the afternoon. Here is a picture of the stall, ready to go but sans visitors.


After the first hour, I left the stall in the capable hands of John Read and Ian Peatfield for the morning. We had agreed a kind of shift system – I didn’t want everyone arriving first thing and us all getting tired mid-afternoon. I went and found a cafe for a quiet read. When I returned after lunch Ian had finished his stint, Alex Corner and Noel France had joined John, and the stall was abuzz! Here is a photo.


Apart from the combination of bamboo cane ‘matches’ and plastic plate ‘coins’ for some of the oversized puzzles leading to a plate spinning class, everything was going as planned. Soon we were joined by Kathryn Taylor and the five of us spent the afternoon rushing around after wave-upon-wave of pupils. That every few minutes another pupil was dragged away from the stall, “put that down now, we’ve got to leave”, by their teachers was, I think, a sign of success. Here’s one more picture from the afternoon.


Overall, I am very pleased with the stall we made and the team who ran it. My first science fair and a very pleasing experience indeed. I hope some of our visitors saw some interest in mathematics and the couple of hundred who took the advice sheet might learn something about approaching problems. Now, to find somewhere to store my new ‘puzzles stall kit’ for next time!

Congratulations should go to David Ault and his team for organising the fair which, as far as I can tell, went very smoothly.