https://bsky.app/profile/jlanier.bsky.socialhttps://bsky.app/profile/jlanier.bsky.social/post/3movnfrnw2s25What do mathematicians do? How do they make new mathematical discoveries? Why does that matter for K-12 math education? If you are a math teacher and you are curious about these questions, join in on "21st century mathematics" in July! Free, online, and flexible. https://www.youtube.com/watch?v=5UIxJVvbI0022 Jun 2026 19:42 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3movnfrnw2s25https://bsky.app/profile/jlanier.bsky.social/post/3movnfrnw2s25What do mathematicians do? How do they make new mathematical discoveries? Why does that matter for K-12 math education? If you are a math teacher and you are curious about these questions, join in on "21st century mathematics" in July! Free, online, and flexible. https://www.youtube.com/watch?v=5UIxJVvbI0022 Jun 2026 19:42 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3movnfrnw2s25https://bsky.app/profile/jlanier.bsky.social/post/3montw55tlk25Hi! In July I'm once again running a free online 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: https://justinlanier.org/21st-century-mathematics-2026/19 Jun 2026 17:17 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3montw55tlk25https://bsky.app/profile/jlanier.bsky.social/post/3montw55tlk25Hi! In July I'm once again running a free online 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: https://justinlanier.org/21st-century-mathematics-2026/19 Jun 2026 17:17 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3montw55tlk25https://bsky.app/profile/jlanier.bsky.social/post/3mnfojzetk22e@nhoskee.bsky.social @triangleman.bsky.social Hi! I haven't run across any Summer of Math announcements for this summer. Any updates for this or future summers at this time? Thanks!03 Jun 2026 17:54 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3mnfojzetk22ehttps://bsky.app/profile/jlanier.bsky.social/post/3mekizljeck2rTIL that Fibonacci dedicated his famous book “Liber Abaci” to one Michael Scott. 😂 https://media.tenor.com/WYcP64486i8AAAAC/h2di-michael-shocked-happy.gif?hh=498&ww=48911 Feb 2026 03:12 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3mekizljeck2rhttps://bsky.app/profile/jlanier.bsky.social/post/3mdbt5rl2o22s@jonbois.bsky.social watching football25 Jan 2026 22:54 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3mdbt5rl2o22shttps://bsky.app/profile/jlanier.bsky.social/post/3m4ofagamvk24If 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!02 Nov 2025 20:54 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3m4ofagamvk24https://bsky.app/profile/jlanier.bsky.social/post/3lnibd6mq2s2r“21st century mathematics”: a free month-long online enrichment program for math teachers. Info + register: bit.ly/21math2025 Video part 1:23 Apr 2025 13:10 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lnibd6mq2s2rhttps://bsky.app/profile/jlanier.bsky.social/post/3lsksoxkzls24TIL 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"27 Jun 2025 04:32 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lsksoxkzls24https://bsky.app/profile/jlanier.bsky.social/post/3lsbqkfuhfs2aWe 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.23 Jun 2025 14:00 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lsbqkfuhfs2ahttps://bsky.app/profile/jlanier.bsky.social/post/3loj54btkbk2rhttps://www.nytimes.com/2025/05/05/us/politics/pete-hegseth-military-cuts.html06 May 2025 14:52 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3loj54btkbk2rhttps://bsky.app/profile/jlanier.bsky.social/post/3loabsccvyc2eBig day here in Australia.03 May 2025 02:22 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3loabsccvyc2ehttps://bsky.app/profile/jlanier.bsky.social/post/3lnunun4p3k2rTen 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: https://justinlanier.org/21st-century-mathematics-2025/28 Apr 2025 11:26 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lnunun4p3k2rhttps://bsky.app/profile/jlanier.bsky.social/post/3lnunun4p3k2rTen 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: https://justinlanier.org/21st-century-mathematics-2025/28 Apr 2025 11:26 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lnunun4p3k2rhttps://bsky.app/profile/jlanier.bsky.social/post/3lnibd6mq2s2r“21st century mathematics”: a free month-long online enrichment program for math teachers. Info + register: bit.ly/21math2025 Video part 1:23 Apr 2025 13:10 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lnibd6mq2s2rhttps://bsky.app/profile/jlanier.bsky.social/post/3lmvpgbwmvc2rHi! 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: https://justinlanier.org/21st-century-mathematics-2025/16 Apr 2025 04:01 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lmvpgbwmvc2rhttps://bsky.app/profile/jlanier.bsky.social/post/3lmvpgbwmvc2rHi! 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: https://justinlanier.org/21st-century-mathematics-2025/16 Apr 2025 04:01 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3lmvpgbwmvc2rhttps://bsky.app/profile/jlanier.bsky.social/post/3llpofbdew22j"𝘉𝘳𝘪𝘯𝘨 𝘐𝘵 𝘖𝘯: 𝘐𝘯 𝘐𝘵 𝘵𝘰 𝘞𝘪𝘯 and 𝘞𝘦𝘴𝘵 𝘚𝘪𝘥𝘦 𝘚𝘵𝘰𝘳𝘺 are basically the same movie. They're romeomorphic."01 Apr 2025 01:02 +0000at://did:plc:5aiz7eifyvre7nw53t5lldl6/app.bsky.feed.post/3llpofbdew22j