Take three pounds of mathematicians. Peel, remove any stones, and place in a pan with a little water and sugar. Bring to a simmer and stir occasionally. Test the jam on a cold saucer until it wrinkles when you push a finger through it.

Actually, that’s not how you start a MathsJam at all. I waited for some time for someone to create a Cambridge MathsJam, having seen the success of the ones in other cities and enviously following events on Twitter wishing I could be there. After attending the first two MathsJam annual conferences and having a jolly good time, I realised that everyone else in the Cambridge area was also waiting for someone else to start a MathsJam, and despite having the organisational skills of a very disorganised thing, I thought I’d give it a go.

I asked a few close friends if they’d be interested in coming along, and got in touch with Katie Steckles who organises the Manchester MathsJam. She provided me with oodles of advice from her own experience, together with some words of wisdom from Matt Parker of London MathsJam. Then I contacted the pub where we tend to go for pub lunches from work on the rare occasions that I’m allowed out of the NRICH office, and asked if they could reserve a couple of tables for us. “Probably between half a dozen and eight people I would guess”, I said when the landlord asked how many to expect.

So we had a venue, and a date. Now came the publicity! I sent a couple of tweets, and they were picked up and retweeted. Now that we had a venue we’d been added to the MathsJam website, so people started getting in touch that way. The close friends who had encouraged me to go through with this then invited everyone they could think of, and those people also mentioned it to their friends. I emailed the landlord: “Actually, it’s going to be more popular than we thought – maybe as many as a dozen or 15 people!”

While I was out shopping, I saw some bits and pieces – some of those wooden puzzles with rings that you have to disentangle, some playing cards, a set of dominoes, and I started building a MathsJam resource bag. I also stocked up on paper and pencils, chucked a couple of calculators in, and dug out one of my spare Rubik’s Cubes. Then yesterday evening I turned up early at the pub with my little brother in tow, got a drink and something to eat, and spread the maths paraphernalia out on the table so that people would know who we are.

“Is this the MathsJam?” “We’re here for the MathsJam.” “Hello, I’ve brought some maths!” The lovely thing was that people just sat down and started talking to each other. I’d prepared a sheet with a few NRICH problems to use to break the ice, and this proved to be a good idea, because once people were talking they started sharing other problems, card tricks, origami. I kept an eye on Twitter and read out some problems that were being worked on elsewhere, although we didn’t get round to sharing much of what we were doing. At one point, I counted 23 people in our corner of the pub, all working on maths and enjoying a drink! As people started to drift off at the end of the evening, I heard a lot of “Cheers, see you next month” and “I’ll bring you that problem I told you about”. I regret that I didn’t get the chance to talk to everyone and I didn’t catch everyone’s names, but I have high hopes that the people I didn’t spend time with will come back next month, and the month after, and the month after that…

A huge thank-you to everyone who made the first Cambridge MathsJam a success. Here’s to many more!

These are the problems I put out on the table at the start of the evening. We are building a collection of similar problems on NRICH and eventually they’ll have their own page. They should require no knowledge beyond A Level, and many can be solved using GCSE level content.

https://nrich.maths.org/249

https://nrich.maths.org/251

https://nrich.maths.org/279

https://nrich.maths.org/301

https://nrich.maths.org/327

*The next Cambridge MathsJam will be Tuesday 21st February at the Castle Inn, Cambridge. Visit the website if you want to join the mailing list. To find a MathsJam near you, see http://www.mathsjam.com*