The following information is lifted from the Official MathsJam page:
MathsJam (or MathJam as it is known in North America) 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.
We meet on the second to last Tuesday of every month, from 7 pm in the evening. Events happen simultaneously in locations around the UK (and the world!) For more details of local events, click the links above, or visit the map of current and potential MathsJams.
You can follow our activity by looking at the @MathsJam twitter feed.