Both kinds of MathsJam

By on 11/06/2018
Cake by Sam Hartburn. Photo by Tom Briggs.

There are two things both called MathsJam and we’re going to try to explain both. We think it would be nice for there to be more of the first kind around Europe (and the world) and hope someone reading this will agree. And we’d like to encourage people from around Europe (and the world) to consider coming to the second one.

An article by Adam Atkinson


Monthly local MathsJams

Monthly MathsJams happen in various cities around the world, usually but not always at 19:00 on the penultimate Tuesday each month. They are typically held in pubs. A list of current cities can be seen at, which also describes the nature of the events as “MathsJam is a monthly opportunity for like-minded self-confessed maths enthusiasts to get together in a pub and share stuff they like. Puzzles, games, problems, or just anything they think is cool or interesting.” Looking specifically at the “rest of the world” list at we see that there are currently 8 Jams listed in Europe outside the UK and Ireland.

Concretely, what happens at a Jam? This is almost entirely up to the people at the Jam itself. The general idea is to turn up and “do stuff” with no particular programme, timetable or agenda. The start time is just an idea. It can have elements of “show and tell” if someone has just come back from an event elsewhere like the Gathering for Gardner in Atlanta or the Recreational Maths colloquium in Lisbon. Someone might have a new book or puzzle, or have recently heard a new problem. Someone might want to ask other people what the point of group theory is, or if they’ve ever used linear programming in “real life”.


One thing which is made available each month by Katie Steckles (, @stecks on Twitter), overall administrator of the monthly mathsjams, is a sheet of problems called the “Shout”. Each month the “Shout” contains problems/games/activities offered by one Jam for Jams around the world to try. April 2018’s Shout came from Pisa (in Italy), and May 2018’s was from Newcastle (in the UK). It’s not compulsory to do the problems on the Shout, or even to look at them, but it seems likely that most people do at least some of it.


If there is a Jam somewhere near you, you could go and visit it. If there isn’t, you could start your own. Find a place to hold it, decide on a time and date (19:00 on the penultimate Tuesday isn’t _compulsory_) and let Katie know. There probably need to be at least two of you. Katie will add your city to the list, and arrange for emails to to go to you. You will be able to amend your Jam’s page on the MathsJam website to deal with changes in location or time, or a cancelled meeting. If you hand over the contact role to someone else or shut the Jam down completely, let Katie know. The contact person doesn’t _need_ to attend every Jam. I am absent from my own 1-2 times a year and my predecessor missed at least 2 out of 3.

Local Jams are _encouraged_ to set up Twitter accounts, which will be retweeted by the main MathsJam account on Jam day. This leads to a sense of community as Jams around the world discuss their partial solutions to Shout problems, etc. However they are not _required_ to set up Twitter accounts.

You might be thinking that you could meet some of your friends in a pub to do maths without needing to do any of the above. Well, of course you could. But the existence of a MathsJam in your town could bring out local recmaths people you had no idea even existed. And you can benefit from MathsJam tourism: people from
elsewhere who are away from home on Jam day can visit your Jam, and if you’re away from home on Jam day you can visit theirs. For purely selfish reasons, I’d love there to be a Jam in Catania since I go there several times a year. If anyone reading this can help arrange that, that would be lovely!

How many people go to a local Jam? This of course varies a lot, but 3 to 8 seems to be about usual with London as a possible outlier. The last time I went to London it seemed to have 20-30 people. It should be mentioned that local Jams are not intended for children. As explains, “MathsJam is an event for adults to meet and socialise, which is why they are mainly held in licensed premises, where under-18s are not allowed.” Any adult who likes maths enough to come is welcome. You can see some photos of a mathsjam in progress at

Why is the problem sheet called the “Shout”? My guess is that this is because monthly MathsJams were originally invented by Australian mathematician Matt Parker (@standupmaths on Twitter, and part of the Festival of the Spoken Nerd comedy trio), and when it’s “your shout” in a pub in Australia you buy a drink for everyone in your group in the pub. This may also be used in some parts of the UK, though the name for this I had heard was a “round”.

The following problems are not taken from old Shouts, but could be taken as examples of some of the sorts of things that could appear in a Shout. My selection of these probably says more about me than it does about the Shout.

  1. Find an arithmetic progression of three integers whose product is prime.
  2. A positive integer n is “semi-1” if exactly half of the integers from 1 to n have a 1 in them (when written in base 10). For example, 2 and 16 are semi-1. 2 is semi-1 because 1 has a 1 in it and 2 does not. 16 is semi-1 because 1, 10, 11, 12, 13, 14, 15 and 16 have a 1 in them and 2, 3, 4, 5, 6, 7, 8, 9 do not. Are there finitely or infinitely many semi-1 numbers?
  3. What is the only integer whose English name has its letters in alphabetical order?
  4. I give you a heap of n tokens. You may divide it into subheaps as you wish. I will then multiply all the sizes of your subheaps together and pay you the product in pounds. How can you get as much money out of me as possible?


The MathsJam Gathering (aka “Big MathsJam” or “Annual MathsJam”) (

Once a year, in Stone, Staffordshire in the UK, there is the “MathsJam Gathering”. This year it will be on the 17th and 18th of November, though anyone travelling from overseas would be best advised to arrive on the 16th. This is organised by Colin Wright (@colinthemathmo on Twitter), aided by Katie Steckles, Matt Parker and others.

Unlike monthly Mathsjams, the annual one does have a programme and a timetable. There are about 50 5-minute talks across two days. The people giving the talks are basically the same as the people attending the event. After you register for the event you get the chance to offer a talk. The talks happen in blocks of about 7 or 8 and there are long intervals between the blocks so that during the intervals you can go to talk to speakers, look at games and puzzles on other people’s tables, etc.

The MathsJam room during the evening activities. By courtesy of the site Chalkdust

The MathsJam room during the evening activities. By courtesy of the site Chalkdust

There are also competitions at the big Jam. There is a baking competition, with prizes for best looking cake, best tasting cake, and best maths. You can see the 2017 cakes here: and an article about the making of one of them here There is also a competition competition. You enter this by proposing a competition that attendees can enter. You can offer a prize with value of at most one pound. At the end of the Jam winners of the competitions are announced, and the competition with the most entries and the competion judged to be best get prizes in the competition competition. Over the years some of the entries have become rather meta. There is a MathsJam Jam where people sing maths versions of supposedly well-known songs. The songs from 2017 can be found at

On the evening of the first day, there are activities arranged by people attending the event. These can be almost anything. Mathematical crochet? Medieval French poetry reading? Learning to play Go? Suggest and run your own activity! o get an idea of the variety and style of the talks at previous big Jams you can look at – a few big MJ talks can be found on Youtube.

One of the standout talks at the 2017 Gathering was this poem by Zoe Griffiths which you can hear performed by her about 25 minutes into

Registrations for the 2018 event opened in late May and the registration page is at

Chalkdust magazine has written about annual Jams here and here

(Note that while I am the organiser of the Brighton MathsJam this does not imbue me with superpowers. I am not one of the actual MathsJam organisers and do not claim to be representing them. I just think it might be nice for more cities in Europe (and elsewhere) to have local Jams, and that possibly more people from outside the UK would enjoy the annual Gathering / Big Mathsjam.)

A similar event to Big Mathsjam is the Recrational Maths Colloquium in Lisbon in odd-numbered years. The next one is in January 2019 and details can be found at

Adam Atkinson


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