We were invited to read from our books, which I did of course. But first I had some opening words, which I thought I'd share with you here. I'll share video too, once that's available.

TIL that Fibonacci dedicated his famous book “Liber Abaci” to one Michael Scott. 😂

@jonbois.bsky.social watching football

Really nice piece on math and democracy here. (gift link) www.nytimes.com/2025/11/03/s...

If you teach Year 6 maths in the UK and you'd be willing to Zoom chat briefly with a pre-service teacher in the US for a class project, let me know? Thanks!

I presented on this problem today! You can find the slides here: docs.google.com/presentation... I don't use speaker notes (just vibes) but I think a recorded version exists and I'll try to link to it if/when I can. cc #iTeachMath ♾️ bcc #MathSky 🧮

Yesterday I spent a fascinating morning talking maths with a group of GPs. All professions require some level of numeracy, but doctors face particular challenges when communicating mathematical ideas. I've written up a short blog: robeastaway.com/blog/gp-maths

Applications are now open for our International Visitor Program, open to #mathematicians to visit Aus 🐨 between July '26-'June 27, or March '26-June -27 (Aus/NZ citizens) 📅 Apply by Aug 1, info: mathematical-research-institute.sydney.edu.au/internationa... Please share with your networks 🔁 #MathSky

“21st century mathematics”: a free month-long online enrichment program for math teachers. Info + register: bit.ly/21math2025 Video part 1:

TIL that we narrowly missing lugging around not only the monikers "imaginary", "negative", "complex", and "irrational" for numbers, but also "fictitious limits". Real glad for that. 😅 from MacTutor's "The real numbers: Stevin to Hilbert"

We are two weeks out from the start of "21st century mathematics", a program I run for K-12 math teachers. (Register now!) The program helps teachers connect the math they teach with some math that has been discovered in the 21st century. The program is flexible, free, & online.

"While everyone is glad to have a much-deserved break from the routine of early mornings and late evenings, as teachers we often end the school year thinking about the things we 'just didn’t have time to cover'." Read NCTM President @latrendak.bsky.social's full message here: nctm.link/a3H7t

Have you followed along with Math On-A-Stick and wondered what it would take to make this kind of joyful, creative math happen in your locality? Well, let's gooooooooooooooo www.mathhappens.org/math-at-the-...

Big day here in Australia.

Ten squares. The first example has perimeter 14. The second one has perimeter 22. Can anyone find ones with smaller or bigger perimeters? Or other examples that match these? Intrigued? Check out "21st century mathematics", an enrichment program for teachers: justinlanier.org/21st-century...

Ten squares. The first example has perimeter 14. The second one has perimeter 22. Can anyone find ones with smaller or bigger perimeters? Or other examples that match these? Intrigued? Check out "21st century mathematics", an enrichment program for teachers: justinlanier.org/21st-century...

Are you a mathematics teacher? Would you like a taste of 21st century mathematics? See the link below to join a program for teachers run by Justin Lanier @jlanier.bsky.social —stay for as long as you like, explore with friends, & get your own insights into accessible, deep questions in math

“21st century mathematics”: a free month-long online enrichment program for math teachers. Info + register: bit.ly/21math2025 Video part 1:

Hi! In July I'm once again running a program for K-12 math teachers called "21st century mathematics". Its goal is to help teachers to connect math they teach with some math that has been discovered in the 21st century. Pass it along! Info+register: justinlanier.org/21st-century...

Hi! In July I'm once again running a program for K-12 math teachers called "21st century mathematics". Its goal is to help teachers to connect math they teach with some math that has been discovered in the 21st century. Pass it along! Info+register: justinlanier.org/21st-century...

"𝘉𝘳𝘪𝘯𝘨 𝘐𝘵 𝘖𝘯: 𝘐𝘯 𝘐𝘵 𝘵𝘰 𝘞𝘪𝘯 and 𝘞𝘦𝘴𝘵 𝘚𝘪𝘥𝘦 𝘚𝘵𝘰𝘳𝘺 are basically the same movie. They're romeomorphic."

Find the derivative of f(x) = sin²(x) + cos²(x) in two different ways.

Here's the first page of Radical Equations; I hope it grabs your attention! It's available from lots of independent booksellers, and it's available digitally via Kindle and Audible. (Ask your library to get a copy!)

Advice please: Someone registers for a program I run (through a Google Form) & gives me their email address. But when I try emailing them later, maybe it gets sent to their spam, or maybe they mistyped and I receive an error message back. What's a good way to automate an email confirmation check?

Reflecting on explorations in math place, and something called the Rosenthal Prize: fivetwelvethirteen.substack.com/p/exploratio...

Alright, help me fill up this starter pack. Are there other current K-12 classroom teachers who want to be added, or have cutbacks reduced the math teaching community to this list of 64 (wonderful) individuals? 😂

Who are you cheering for tonight? - 2024 - 2025 - I just hope it's a good game.

If you enjoyed this median-mode-range prompt, check out this "averages inquiry" that I ran across, over on Inquiry Maths. Lots of great stuff! www.inquirymaths.com/home/statist...

Let's have some numbers so that their median is 4, their mode is 2, and their range is 10. What are some possibilities? And then: what could the mean of such a collection of numbers be? What *couldn't* their mean be?