Hi! 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: justinlanier.org/21st-century...

Please Use AI

In #MathsToday we talked about cryptography. First, how cryptographic systems don't matter if you just share your data (there are many examples). Then rot, substitution, one-time pads, Vigenère, Enigma, and finally public-key. #mtbos #ITeachMath

"They're trying to do the thing in a way which is so general, that they can't possibly build on that. If they build on that they're building on top of confusion and vagueness." -- Bill Evans Wonderful description of how important it is to take your time when learning and build a good foundation.

Excited to be named a CSTA Responsible AI Fellow.

This month marks the 20th anniversary of my entering the classroom as a teacher! I was just going through a folder from my first Computer Science course (2009) and am not surprised by myself. Class #1 was "Ethics" #TeamCompSci #ITeachCS #CompSci

Here are some of my favorite #ProblemSolving questions from the April Calendar... April 9: decimal expansion of 1/17 April 14: square roots of square roots (Check out Really Radical post for more!) April 28: shortest path in a circle and square #iTeachMath karendcampe.wordpress.com/2026/04/22/r...

I never met Dr. Nancy C. Dunigan, but I have a copy of the 1981 NCTM Yearbook that once belonged to her. I occasionally get a used math book and can find information about the previous owner. She sounds like a real swell lady and dedicated educator. www.dignitymemorial.com/obituaries/l...

It looks like there are some amazing presentations from teachers in the program for #NCTMDen26. I'll be presenting on the importance of computing in mathematics and how basic familiarity with a numerical computing platform can open up new worlds of beautiful mathematics. #ITeachMath #mtbos

I really appreciate @elizabethwithaz.bsky.social's reflections on how she explored the social impacts of technology with her students by introducing them to the people - the ghost workers - whose labor makes “AI” systems possible. Read this week’s @civicsoftech.bsky.social and find the lesson at:

What does it look like to critically examine AI in the middle school Computer Science classroom? www.civicsoftechnology.org/blog/introdu...

I'm not joking when I say mRNA technology is more important than "AI" and it's a tragedy we're throwing billions into one while our government is aggressively defunding the other.

This is the first year of a new course I built called Computing and Data Sciences. The tools used this year: Semester 1: • Whiteboards • LaTeX (on overleaf) • Sheets + Desmos visualization Semester 2: • Python in Colab with: - NumPy - Pyplot - Pandas #ITeachMath #TeamCompSci

I'm so lost in AI debates at this point. I would love for: 1. Someone to propose the use of a specific tool. 2. We actually vet that tool.

AI is broken. Everywhere you look. Not just "bias", but just broken systems being deployed out into the world. There used to be this notion of an actual finished product versus proof of concept... #AIinEducation

Education researchers, I still have yet to see a study on the most efficient learning we know of: The 40 second slow-walk of a student who just took the test dumping a full unit worth of knowledge into another student's brain as they pass through a door in opposite directions. #ITeachMath

This is so well done. 👌

mathematicians: This is the Schlüsman-Katsuhira transform. It took researchers over 250 years to discover. Only 30 people in the world know how it works. tech artists: This is the Schlüsman-Katsuhira transform, or as we call it in the biz, "ol' Schlussy". We use it for realistic cheese textures :)

We recently looked at the very user-friendly Forced Expiratory Volume (FEV) data set as an exercise in data slicing and visualization: colab.research.google.com/drive/1u7qb6... Got an excited message from a student: "We think we can show that smoking is good for your lungs!" #ITeachmath #mtbos

"AI Literacy" means being a good tech consumer. This is user acquisition, connecting students with products as young as possible. It is data collection and surveillance. What will this program look like? They don't know yet. The goal is to push product. Education is secondary at best here.

I’ve got a couple lessons you might find useful as next steps w this group of students in the “Global Forecast” unit. See “Are They Related?” and “The Emissions Equation.” Maybe also “Degrees of Impact” docs.google.com/document/d/1...

In #MathsToday we started our feature-engineering project with 0s and 1s from MNIST Given a spreadsheet or DataFrame where each row contains 784 pixel values representing an image of a hand-written digit, how can we distinguish a 0 from a 1? #ITeachMath #mtbos

Yes, this is real.

In #MathsToday we modeled CO2 concentration as reported from gml.noaa.gov/webdata/ccgg... One student got quite close to capturing the seasonal fluctuation with: a sin(bx +c) + d + ex +fx^2

New Puzzle: Daily Desmos #3 Can you recreate this? -> https://dailydesmos.com/home/daily-desmos-3

Paired media.

N.S. Borwein and Veselin Jungić. 2025. A Survey of Experimental Mathematics for Education. Maple Trans.5,1, Article 22378 (February 2025), mapletransactions.org/index.php/ma... #MathEdPaperOfTheWeek #mtbos

I searched @nctm.org pub archives for 'computing', 'programming', 'monte carlo', and some others. Then I scrolled a few thousand pages looking for articles that contain code in them. This is what I've found so far. #ITeachMath #mtbos

1969

In #mathstoday (last week) we investigated several datasets. Students generated data questions, including one about what makes YouTube videos more popular. This plot made for a lot of great discussions about causation! #ITeachMath #mtbos

All robots have simple things they struggle with. This includes software chatbots. But in the real world robots fall over and break. In software we just run it again and again until we get an output we like and then forget all the work we put in to correct bad results and call it revolutionary.

In #MathsToday (tomorrow) we are looking at the results of the 2025 Rubik’s WCA World Championship. All of my Data Science students know how to solve a Rubik's cube (it was our first assignment), so they emotionally invested in these tournaments 🤣. We'll look at rankings using different averages.

December 2025 through February 2026 was the 2nd warmest winter on record for the Contiguous U.S. according to Prism climate data. The widespread record to near record warmth in the west easily outweighed the cool temps in the east. 🔥🔥🔥

The March Calendar of Problems is here! Enjoy some #ProblemSolving yourself or with students. Let us know your thoughts & working-out here or on post. #MTBoS #iTeachMath #T3Learns #RecreationalMath #MathSky #MathsToday karendcampe.wordpress.com/2026/03/01/m...

The 7yo looking out the window as we are driving. 7yo: "The moon is moving so fast!" Me: "Actually, parallax is..." 7yo: "Ooooh you don't think 2300 miles per hour is fast?!"

In #MathsToday we read Chapter 3: Arms Race - Going to College, from Weapons of Math Destruction by Cathy O'Neil. Students annotated, discussed in groups, and will share some reflections in writing.

Honestly, this is the kind of organic messaging @prisonculture.bsky.social was talking about earlier. We don't have to wait for the media to take up these issues on their own. Make it all about these issues.

I had one of these beautiful shapes hanging in my old classroom for years! Tangent: this picture was the data from a pendulum lab. I ask students to: 1. Measure the period of a pendulum 2. Measure 10 swings then divide by 10 3. Measure 10 swings again, but this time do a good job Never fails.

A text that is great for #GuessTheYear! "The notion that we understand how mental capacities develop well enough to dare to control their development is not just an exaggeration; it is a pack of nonsense, and we rely on it at our students' peril." #mtbos #ITeachMath #NCTM

Normalize laughing derisively in men's faces when they deserve it.

Really stretching hard to make the math jokes work in this chapter on Number...

Teachers are great. Had an awesome PD day today. Every teacher there was simply a generous kind-hearted person dedicating a career to encouraging and supporting young people in exploring their interests, doing their best, and leading happy lives.

In today’s #404DeepDive, @jasonkoebler.bsky.social gets into Ring’s new feature Search Party which was advertised at the Super Bowl which essentially turns the entire neighborhood into a security dragnet. Read more: www.404media.co/with-ring-am...

I think learning/teaching is about the dance between explicit understanding and our implicit habits, and I think this is confusing, and I think this is also what's confusing about being a person more generally. pershmail.substack.com/p/understand...

In #MathsToday we found sums by creating sequences with NumPy.

In #MathsToday we explored the palmer penguins data set from allisonhorst.github.io/palmerpengui... and did some manual feature engineering.

Time for winter #ProblemSolving! Here's the February Calendar of Problems for you and your students. Tell us your working out here or on the post. ENJOY! #MTBoS #iTeachMath #RecreationalMath #MathSky #MathsToday #T3Learns karendcampe.wordpress.com/2026/02/01/f...

In class yesterday I was talking about heat transfer & I mentioned electro-magnetic energy. I then spent around 20 minutes answering fantastic eager questions about the EM spectrum, particle-wave duality, frequency and color, human physiology and perception, etc. And I didn't even make any of it up!