Buying hot dogs today. The prices per 100g on the signs are a bit blurred, they were 27.7p per 100g for the jar of 12 and 43.4p per 100g for the jar of 6. After staring at them for some time, and using a calculator to double check, I did buy the jar of 12 as it was the cheaper option. #UKMathsChat

Has anyone experimented with scoring points in SET? Playing with people of different experience levels and thinking about how to slow down the quicker players to give the others a chance to build that experience. How about scoring a set by 1pt for every attribute that differs? #UKMathsChat #mtbos

Should've taken a picture of the Christmas tree this morning. Then I could've made a real-life version of that "Xmas - Ymas - Zmas" joke.

Hogfather is 99p as an ebook at the moment. The publisher must've heard about @teakayb.mathsy.space 's readalong.

Waterstones in Oxford has recently moved across town (nearer the Westgate, further from Blackwell's - which they now own). Some things didn't change in the move. They still stock Good Books. Strong recommend for Christmas.

New blog post about the history of my collection of geometric visualisation puzzles Jenga Views. BONUS: I've added even more puzzles! cc @joeldavidhamkins.bsky.social davidkbutler.xyz/2025/12/11/j...

New blog post for maths teachers: "Things I assumed you knew" www.resourceaholic.com/2025/12/thin... Comments welcome! #ukmathschat

Strong recommend. Especially the signed bit. #UKMathsChat #mathsky

It is an acceptable risk that some people who don’t “deserve” it accidentally get help, if it means everyone who needs it is guaranteed to get help.

@catrionaagg.bsky.social the image didn't show in preview

Half my y12 furthers were out today, so I threw a @catrionaagg.bsky.social problem at them and thoroughly enjoyed the next hour! They got the answer, modulo some numbers and by using trig. So next challenge is to remove the trig. #MathsToday #ALevelMaths #UKMathsChat

For the second time today, my initial attempt at coding something has worked without me needing to muck about with it to fix, for example, an off-by-one error. I'm not sure in what universe I've found myself, but it ain't the one I usually inhabit!

I, er, um, well, kinda, sort of, ... In short, I haven't fully processed the existence of this yet. But I thought you should all know about it anyway. www.bbc.co.uk/news/article... #mathsky #ALevelMaths #UKMathsChat

I tried something different to help an #ALevelMaths student who was stuck with a question: instead of telling them what to do, I wrote down my thoughts about how I would solve a question (kind of like @davidkbutler.bsky.social does with #TryMathsLive, except I never actually did the question).

Turns out advent only has twelve days - feel like there was another option there, but I just can't think of it. Anyway, might actually get somewhere this year! #AdventOfCode2025

'Ti's the season, as they say! Ask, and ye shall receive.

Does anyone know of a Christmas-themed activity on loci in the complex plane? Bit niche, I know, but surely *someone* has made one. #ALevelMaths #UKMathsChat

Reposting for the early morning g crew. And I've just spotted the autocorrect for "cosines". Got to get that into my teaching. #UKMathsChat #mathsky #MathsToday

I decided not to read the replies until I had had a go myself. I think it's very hard to avoid the "but I know what the answer us" trap. Here's what I tried. I started with x=tan(u), since that works if we remove the square root. That ended up with sec(u). #MathsToday #mathsky #ALevelMaths

New visual aid for algebraic topology just dropped. Connected#Sum #mathsky #UKMathsChat #HoagieHomies

I think it's time to post this again (since the thresholds have been frozen). www.geogebra.org/m/p97htgc3 [please note this for INCOME TAX only]

In #MathsToday a student asked about integrating 1/sqrt(1+x²). We haven't covered hyperbolics yet, but that got me pondering - there is a non-hyperbolic answer, so is there a route to it that doesn't go via hyperbolics? #UKMathsChat #ALevelMaths #ITeachMaths

I enjoyed doing this question with Y7 #MathsToday. I need to remember to revisit this with Y8 when they start standard form - it’s exactly the way I want them to be thinking about it.

Recommendation request: a good first (undergraduate) text in group theory. Thanks! #mathsky #ITeachMaths #UKMathsChat #HoagieHomies

what is ironing if not differential topology

VERY IMPORTANT IDEA: the next academic conference I attend should have a "tea exchange" where we all just bring a bunch of our favorite tea, try each others, and then everyone leaves with some new tea that they liked. This is unironically a 10/10 networking idea and I'm not too humble to admit it.

These new papers on the 'dga of planar loops' look very fun: arxiv.org/abs/2511.15653 🧮

I used this yesterday with Y7. The number line helped them get their heads around the idea that there is one more "jump" than blanks to fill. #MathsToday

This is awesome. I'm a particular fan of it being grouped by *final* grade. I think that is a really crucial aspect of what is presented to students. Rather than saying what will happen to them, describe possible trajectories and ask "what would you like to happen? What will *you* do?"

I'm looking for a thing but my web searching skills are failing me... I was in an online training thing once, and the presenter shared a link to an online map. This map allowed everyone in the meeting to click on the map to indicate where they were in the real world, and then the presenter was […]

❤️ Love this ❤️ @mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!

Coffee will fix it.

🦂🚨🦂 New Chalkdust alert! 🦂🚨🦂 DNA origami, tracks and an interview with El Nombre feature in our AW25 issue! Plus all your favourite puzzles & columns. Read the entire new issue now at chalkdustmagazine.com

An interaction at yesterday's launch of #MathsWeekEngland at the new MathsWorld venue near London's Bankside. Mum with child: "What do you call the type of maths that's here at MathsWorld?" Me: "It's officially called 'fun and interesting' maths" Mum: "Ooh, we love this sort of maths"

Sunday night seems the right time to post a gallery of (I hope!) every one of Catriona's geometry puzzles. notes.mathforge.org/notes/publis... Give it a moment to load ... there's a *lot* of them! #GeometryPuzzles #UKMathsChat #mathsky

Idly perusing the bookcase (sorted by colour, of course) and noticing a few things. Most books by a single author: Terry Pratchett (no contest) #Books #IdleMusings #BookShelfOddities

Batik sonobe today #fiberart #origami #batik #mathart

Just started 2nd order ODEs, decided to start with coupled 1st order. Rationale: 1. Modelling. Start with y'=ky modelling a single population, bring in a second with interaction. 2. Exponential. Solution to single pop is exp, so reasonable to try for double. #ALevelMaths #UKMathsChat #MathsToday

Did not realise that Bees and Bombs had made the leap to BlueSky! #UKMathsChat #mathsky #HoagieHomies

Giant cardioid: version 2.5. Version 1.0 was made using Pex tubing and grommet tape. Version 2.0 was made from laser-cut pieces. The wood was too fragile, and it broke during construction. In version 2.5, I made the pieces wider and I used thicker wood. Success, I'd say! The diameter is about 5 ft.

Interested in studying statistics @ox.ac.uk? Join us for our Postgraduate Open Day and find out more about the courses we offer. 📅 Wednesday 19 November 2025 ⌚ From 1pm 📍 In-person and online 📃 Please register by Monday 17 November at: forms.office.com/r/Q6HxgLR16C #postgrad #openday

We're hoping to avoid any interview horror stories this Halloween 👻 We've teamed up with @brasenoseoxford.bsky.social to host 11 online interview workshops 3–17 November for anyone applying to @cam.ac.uk or @ox.ac.uk for undergraduate courses. Find out more & sign up:

Recently I was playing with the Square-Sums Puzzle (as explored previously by @standupmaths.bsky.social on Numberphile) and realised it would be fun for schools. So here is a FREE teacher resource: think-maths.co.uk/square-sums (and enjoy its use being modelled by my in-house mathematician below).

I even found a copy in that intellectual backwater that is Cambridge . @teakayb.mathstodon.xyz.ap.brid.gy

A useful thread for anyone who buys ebooks.

Drove past Cambourne. Lovely rainbow visible as we went by. Perhaps another column for the Large Data Set? #ALevelMaths #UKMathsChat #mathsky

Family member just pondered whether anyone had made an earth sandwich. Thanks to the #HoagieHomies, I was able to answer without hesitation. (Or deviation. Or repetition.)

Math[s] is just an excuse for cut-and-stick activities. #MathsToday #mathsky

They say that if you stay long enough in the Norrington Room then every author in the country will come and sign your book. Spotted in Oxford's unique bookshop - @teakayb.mathsy.space