Big MathsJam
@bigmathsjam.bsky.social
Big MathsJam is the annual UK MathsJam Gathering - an opportunity to meet other maths fans and share puzzles, games and interesting problems. November 22-23rd 2025
Finally, to wrap up MathsJam for this year, Colin Wright got us thinking about compass and straight-edge constructions of a regular pentagon, and how we know such a construction is exact.
November 23, 2025 at 2:37 PM
Finally, to wrap up MathsJam for this year, Colin Wright got us thinking about compass and straight-edge constructions of a regular pentagon, and how we know such a construction is exact.
For the penultimate talk of MathsJam, Nancy Blachman shared a mathematical magic trick that can be accomplished in multiple ways.
See more at
See more at
Cat, Dog, and Mouse Magic
Can you fill each grid with red and yellow tokens?
jrmf.org
November 23, 2025 at 2:37 PM
For the penultimate talk of MathsJam, Nancy Blachman shared a mathematical magic trick that can be accomplished in multiple ways.
See more at
See more at
Raphael Colman talked to us about creating knitting stitch diagrams using Haskell. How can you average colours to make a pixellated image look good knitted?
November 23, 2025 at 2:37 PM
Raphael Colman talked to us about creating knitting stitch diagrams using Haskell. How can you average colours to make a pixellated image look good knitted?
Next, Barney Maunder-Taylor shared what happens when you glue a square based pyramid and a triangular based pyramid together. Can you prove that the volume of the square-based pyramid is twice that of the triangular?
November 23, 2025 at 2:37 PM
Next, Barney Maunder-Taylor shared what happens when you glue a square based pyramid and a triangular based pyramid together. Can you prove that the volume of the square-based pyramid is twice that of the triangular?
And the winner of best circumvention of the rules was Guveer's small box: mathsjam.com/gatheri...
November 23, 2025 at 12:39 PM
And the winner of best circumvention of the rules was Guveer's small box: mathsjam.com/gatheri...
Highlights of the competitions included prizes of one eighth of an issue of New Scientist, and a bar of chocolate wrapped in the full worked solution to the puzzle. Dave's poly filler competition won best competition and got the most entries: mathsjam.com/gatheri...
November 23, 2025 at 12:39 PM
Highlights of the competitions included prizes of one eighth of an issue of New Scientist, and a bar of chocolate wrapped in the full worked solution to the puzzle. Dave's poly filler competition won best competition and got the most entries: mathsjam.com/gatheri...
Ben Handley wrapped up the last session before lunch - he has been exploring skittles, building on previous Mathsjam talks by Clare Wallace, looking at the probability of finding identical packs of skittles. Turns out the distribution of skittles is uniformly independently random!
November 23, 2025 at 12:11 PM
Ben Handley wrapped up the last session before lunch - he has been exploring skittles, building on previous Mathsjam talks by Clare Wallace, looking at the probability of finding identical packs of skittles. Turns out the distribution of skittles is uniformly independently random!
Next up, Michael Borcherds shared with us his favourite shape - the 14th Stellation of the Icosahedron - and how to 3D print it. Try it yourself:
14th Stellation of the Icosahedron (modular 60) by murkle MakerWorld: Download Free 3D Models
Boost MePlease boost for more models like this!You need to print 60 copies of this and superglue 240 magnets (6x3). Seven fit on a plate (P1S) so in that case print 9 plates (or 8-and-a-bit) The three plates have different depth magnet holes. Plate 3 works for the cheap magnets from AliExpress which (in my experience) all seem a little thinner than 3mm See pictures for assembly, make sure the magnets have the correct N/S orientation: each piece has 2 N and 2 Sthe “middle” 2 holes have the same orientation and the “edge” 2 have the opposite to thatglue a few and TEST that they assembly OKI've printed this in Elegoo silver Silk PLAYou can modify the magnet holes here https://www.geogebra.org/classic/n4fahkbc (change eg depth and export as STL)
makerworld.com
November 23, 2025 at 12:11 PM
Next up, Michael Borcherds shared with us his favourite shape - the 14th Stellation of the Icosahedron - and how to 3D print it. Try it yourself: