For anyone who watches – or remembers – the Royal Institution Christmas lectures, the Festival of the Spoken Nerd shows will strike a familiar tone as the amiable trio explain the theories behind some ‘wow…’ moments in science.

How this translates into a comedy environment depends a great deal on the attitude of the audience. Last time I saw them, in University College London’s Bloomsbury Theatre, it seemed a real celebration of dweeb pride, as a studenty crowd geeks celebrated their status, cheering spreadsheets and the algebra of toroidal vortices.

Here, in a market town arts centre (oh why wasn’t it a function room, that would have been so much more apt…), it seemed the audience were more into learning than bonding over their nerdiness. So were there laughs? A few… but sage, appreciative nods were certainly more prevalent.

The name of Just For Graphs is not just a cheesy pun, since for this outing, the upbeat trio of Helen Arney, Steve Mould and Matt Parker focus their attention on the visual representation of data, that hack old comedy topic. Though strictly speaking, these are not graphs but ‘charts, plots and diagrams’ as needs explaining for the pedants in the room…of which the are, of course, a non-trivial percentage.

Lots of comics these days might cite Venn diagrams to suggest they’re smart. Here they do Euler diagrams too – and know the difference. And when they display E=mc² on screen, it has to come with the disclaimer that it’s only a valid approximation within the weak field limit.

Yet it’s a mixed ability group, from the hardcore nerds to the ‘sci-curious’, which has to be carefully played. Demonstrating waves via the Mexican variety might seem a little simplistic to anyone with a GCSE, whereas to be properly excited by the beauty of the so-called ‘Tupper’s self-referential formula’ requires a bit of knowledge as to why it’s so impressive.

It’s certainly true that the most monumental feats don’t always make the best theatre. ‘Stand-up mathematician’ Parker’s ability to generate a 10x10 magic square in the time it take Arney to sing a Wicked-inspired song about Einstein’s theory of gravitational curvature isn’t as visually interesting as demonstrating a parabola by throwing a flaming ball in the air, even if the science of the latter is straightforward compared to the mental gymnastics of the former. But playing with fire is fun… and sometimes there’s a sense they’re amusing themselves first and foremost.

Meanwhile, the finest experiment from Mould – who used to be the science guy on kids’ TV – shows the harmonics of a vibrating plate using sugar. An instance of a Blue Peter presenter being found with white powder in good way.

Aside from the maths, the trio have an agreeable chemistry. Parker is the nerd among nerds, which allows even Mould to mock the geek. Meanwhile Arney is often the voice of mediation, as well as the songs, although seems a little under-used here compared to previous Nerd outings.

Just For Graphsmight not quite be the winning formula, but you’ll emerge with a head spinning with facts, and the elegant symmetry of a Venn diagram with five or seven sets – but sadly few gags you can tell down the pub.