Daniel Scher

Some Web Sketchpad news: You can now build customizable activities, choosing from over 60 geometry and algebra tools, and then collect students' work to review all on one webpage. Get started here: geometricfunctions.org/fc/tools/. Feedback welcome!

some neat Claude coded apps from @danielscher.bsky.social www.sineofthetimes.org/coding-up-a-.... I like fraction slice especially. www.sineofthetimes.org/standalone_f...

“If we are not careful, we will lose the experience of struggling to find our way, and the thrill when it all becomes clear. We will lose the habit of searching for the truth… Rather than asking whether AI understands, we should ask whether it will help us understand.”

Three regular hexagons. The smallest has area 6. What’s the pink area? #geometrypuzzle

In each diagram, the green area and blue area are equal

#MathSky I've been obsessed with two-sided ruler constructions recently and I'm now working my way through creating eight blog posts about it. You can see the first two posts starting here. (More will come later as I make the videos). davidkbutler.xyz/2026/06/25/t...

Miko Imura/Hirono Tyle shared a blogpost on this cool heptagon based #tessellation. note.com/tairu_mk/n/n... (in Japanese, but translates well.)

Taught my first #MathsToday lessons of the year! I forgot how much fun this topic is with Year 7. Today we played “guess the method from the calculation”.

Next week, I'm giving a talk at the @momath.bsky.social MOVES conference on the purely probabilistic dice game Left Center Right. Rather than creating slides to explain the rules, I decided to try "vibe coding" to see what I could create using AI. Here it is divisbyzero.github.io/Left-Center-...

The three rectangles are congruent. What fraction of the design is shaded? #geometrypuzzle

Some fun with number bases (2 through 10) in my latest Sine of the Times blog post: www.sineofthetimes.org/more-fun-wit...

Lots of… Ooo, But, No Wait as we explored the statement, ‘Any quadrilateral can be made from two triangles’ in #MathsToday

These triangles are congruent and isosceles. What’s the area of the semicircle? #geometrypuzzle

Four squares. What’s the angle? #geometrypuzzle

NEW post: Cracking the Strategy, when a 4th grader explains her thinking fawnnguyen.substack.com/p/cracking-t...

What fraction of the triangle is shaded? #geometrypuzzle

Four quarter circles. What fraction is shaded? #geometrypuzzle

One of those heart-FULL teaching days: New post: open.substack.com/pub/fawnnguy...

New blogpost on a #mathart lesson we did with preservice teachers and 1st and 2nd graders with some string art type patterns. mathhombre.blogspot.com/2025/05/star... #teachered

This was a no-brainer for me when it came to funding this project on Kickstarter. www.kickstarter.com/projects/bra...

A 'flip' but probably easier than a 45˚ reflection

Kudos to @nytimes.com for covering ARC-AGI in such an exquisite example of interactive data journalism. Amazing spot for @fchollet.bsky.social as well. www.nytimes.com/interactive/...

Look at this! Taken from Satisfraction, the new book from @profsmudge.bsky.social which is available to order now. atm.org.uk/Shop/Satisfr...

Mostly encouraging www.npr.org/2025/03/17/n...

New blog post! "Marvelous Midsegments" Go For Geometry! Episode 5. Activities exploring on all technology platforms: Desmos, GeoGebra & TI calculators. Taking the scenic route 😉 #geometry #MTBoS #iTeachMath #MathsToday karendcampe.wordpress.com/2025/03/16/g...

I’ve just looked up the ppt - the task I used was from @profsmudge.bsky.social’s Algebradabra book - here’s the slide (I can’t get Bluesky to insert a screenshot so this is a low tech version!)

I am incredibly stoked for CMYK games new series of minimal and awesome card games — Fruit Fight sounds very fun and I cant wait to try all of them. Group games of this size are always my favorites www.cmyk.games/collections/...

Arriving at Easter....

Title page from my collaboration with Bugra Giritlioglu. We're reviewing the page proofs now for our book of translated Turkish poetry. Coming this April from Syracuse University Press. press.syr.edu/supressbooks...

Wow...they really banned it 😭 #MathSky #ITeachMath

A starter for my class who have had one lesson of C≈3.14×d. 'Measure the diameter of each circle and calculate the circumference ... and stop bending the rulers.' #UKMathsChat #iTeachMaths

Our first game is now available to play at dailyakari.com ! 🎉🥳🕺 We will be featuring a new Akari puzzle here every day! Hope you enjoy it! 😊 #gamedev #indiedev #sudoku #puzzlegame #godot #wordle

An interactive game by James Tanton that makes interesting use of complex numbers. gdaymath.com/puzzle-apps/...

Here is a nice followup to the zigzag theorem. What is the right analogue of the zigzag theorem for zigzags in the annulus between two concentric circles? How are we to compare the orange area with the yellow area in the annulus? Post your answers!

The zigzag theorem, a selection from Proof and the Art of Mathematics. www.infinitelymore.xyz/p/zigzag-the... #InfinitelyMore #ProofAndTheArt

I wrote about how AI undermines reading, particularly reading books — about summarization and “optimization culture.” And, for paid subscribers, I have a list of recommended books from those I read this year 2ndbreakfast.audreywatters.com/mark-all-as-...

LaTeX/Tikz challenge: Define commands \lune and \lense and then use them to make this season greetings:

(0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)² = 2025 (0³ + 1³ + 2³ + 3³ + 4³ + 5³ + 6³ + 7³ + 8³ + 9³) = 2025 Best wishes to you for the new year! #math #MathSky 🧮 🧪

Great Q posed by @mpershan.bsky.social: is there an app where you draw a distance vs time graph and it makes the velocity vs time graph? No such app seemed to exist, so I wrote one using p5play: rajeevraizada.github.io/Pos_veloc_gr... I hope #iteachphysics & #iteachmath folks find it useful! #EDUsky

2025=1³+2³+3³+4³+5³+6³+7³+8³+9³ and 2025 =(1+2+3+4+5+6+7+8+9)² pinkmathematics.blogspot.com/2014/06/a-sq...

A screenshot of an Excel spreadsheet that makes knot patterns using intercept-toggled graphing.

Here are the biggest breakthroughs that happened in mathematics this year. www.quantamagazine.org/the-year-in-...

What fraction of this regular octagon is shaded? #geometrypuzzle

A mea culpa to all the angry math teachers

Enjoying my cycloid drawing machine.

12 years after his first appearance, Sal Khan was back on 60 Minutes to talk AI. And I have thoughts 2ndbreakfast.audreywatters.com/12-years-and...

My kind of kid!

This is fascinating. I can see why it works algebraically, but no intuition (yet) for why you would expect this to work.

Found issue #1 of Games Magazine in my closet. Can’t overstate the impact this magazine had on my love of puzzles.