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Erick Lee

@theericklee.bsky.social
778 followers 461 following 411 posts

High School Math Teacher | Desmos Fellow | Nova Scotia Math Teachers Assn President. #ITeachMath. I occasionally blog about math at pbbmath.weebly.com

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Reposted by Erick Lee
Carl @mathowitz.bsky.social · 11h
Talking with a parent who, in essence, wanted an "i do, we do, you do" teacher centric math class for their kid Reminded me of when i taught AP Calc. I gave a worksheet on the 1st day which basically had them exploring all of conceptual calculus with no instruction drive.google.com/file/d/1U4_w...
drive.google.com
Day 1 - What is Calculus_.pdf
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DavidPetro314 @davidpetro314.bsky.social · 28/09/2026
[New Post] Ontario Math Links - My favourite #math related links from this week: ontariomath.blogspot.com/2026/09/math... Links and help from @theericklee.bsky.social @howiehua.bsky.social @drrowlandson.bsky.social @nomadpenguin.bsky.social and more #MathChat #MTBoS #iTeachMath
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Jenna Laib @jennalaib.bsky.social · 28/09/2026
New #SlowRevealGraph: Amount of Sugar in Popular Miniature Chocolate Bars How much sugar is there in a miniature candy bar? Compare different "fun size" bars using a scaled pictograph. Link below:
slowrevealgraphs.com
Amount of Sugar in Popular Miniature (Fun Size) Chocolate Bars
How much sugar is there in a miniature candy bar? Compare different "fun size" bars using a scaled pictograph.
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Catriona Agg @catrionaagg.bsky.social · 22/09/2026
I got to do some #MathsToday 😁 using this lovely task with new leads of A Level Pedagogy Work Groups. If you teach A Level anywhere in England, I would really encourage you to contact your local Maths Hub and join a Work Group for 3 days of brilliant free CPD.
Three kinematic graphs labelled A, B, C.

Which one doesn't belong?
Give a reason why each graph might be considered the odd one out.
What is the most obvious reason you can give in each case?
What is the least obvious (but still justifiable) reason?

A suggested sentence structure: "A is the odd one out because B and C both …"
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Miss Morris @morrismaths359.bsky.social · 25/09/2026
#Mathstoday My intervention group had a go at the Doughnut Percents Nrich task. Matching up fraction decimals and percentages nrich.maths.org/problems/dou...
nrich.maths.org
Doughnut Percents | NRICH
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Erick Lee @theericklee.bsky.social · 23/09/2026
Created an esti-mystery formatted for a newsletter where all the clues can be seen at once instead of revealed one at a time. Can you find the number of buttons in the cup? Suggestions for improvements? #ITeachMaths #MathsToday
An esti-mystery formatted for a print newsletter. A picture shows a glass cup filled with small buttons. A series of clues helps you find the exact total.
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Dawn Del Vecchio @dawndelvecchio.bsky.social · 17/09/2026
www.sciencedaily.com/releases/202... Researchers find a Wordle strategy that wins 99% of the time A mathematical strategy that prioritizes information over lucky guesses can solve Wordle 99% of the time #math #maths #MathSky #MTBoS #iteachmath #Wordle #ShannonEntropy #InformationTheory
sciencedaily.com
Researchers find a Wordle strategy that wins 99% of the time
Researchers at Binghamton University have developed a mathematical strategy that can solve Wordle with a 99% success rate. Instead of simply guessing words packed with common letters or choosing the m...
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Erick Lee @theericklee.bsky.social · 19/09/2026
Math teacher at the gym... on the eliptical machine listening to New Order's Blue Monday and thinking, "I could re-create this animation on @desmos.com." Here is the result www.desmos.com/calculator/k... #ITeachMath
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cmcmath.bsky.social @cmcmath.bsky.social · 17/09/2026
We're fortunate to have @MikeFlynn55 for our September third Thursday of each month webinar, 9/17, Free Reg and archived sessions: www.cmcmath.org/online-learn... #cmcmath
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Paul Rowlandson @drrowlandson.bsky.social · 12/09/2026
New blog post - Explores one of my favourite questions to ask after finishing a worked example: What would happen if I changed the question? wp.me/p9t8DE-s8 #mathschat #MTBoS #ukmathschat #iTeachMaths
wp.me
What Would Happen if I Changed the Question?
After completing a worked example on the board, one of my favourite questions to ask is, “What would happen if I changed the question?” More specifically, point to a number or term within the quest…
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Amie Albrecht @nomadpenguin.bsky.social · 10/09/2026
Listening to the recent ICM panel discussion on 'What Is Math For in the Age of AI?' got me thinking about a much older question. What do we value in learning mathematics? Read my latest blog post here: amiealbrecht.com/2026/09/10/s...
amiealbrecht.com
Should we take the keys away? Learning mathematics in the age of AI
Is AI really changing what it takes to learn mathematics? Haven’t we been asking this question for a hundred years?
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DavidPetro314 @davidpetro314.bsky.social · 07/09/2026
[New Post] Ontario Math Links - My favourite #math related links from this week: ontariomath.blogspot.com/2026/09/math... Links and help from @karencampe.bsky.social @awm-math.org @howiehua.bsky.social @mrcorleymath.bsky.social @johannamath.bsky.social and More #MathChat #MTBoS #iTeachMath
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DavidPetro314 @davidpetro314.bsky.social · 05/09/2026
[New Podcast] This episode features @theericklee.bsky.social previewing their Sept 9th @oamecounts.bsky.social FREE webinar "Bigger on the Inside: The Surprising Power of Short Math Routines". More info: talks.oame.on.ca/season-9 #MathChat #MTBoS #iTeachMath
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Fractal Kitty @fractalkitty.com · 27/08/2026
I'm going to run a group - Painting the OEIS. Please share your favorite sequences and why. I'll share what art I do with any of them. #oeis #mtbos #mathArt
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Henry Segerman @henryseg.bsky.social · 25/08/2026
MoMath will host a free online event on Friday, Aug 28 at 12:00pm US Eastern time premiering a new video by Sabetta Matsumoto, Tim Reinhardt, Jürgen Richter-Gebert, and me, on hyperboloids made out of sticks and how they move. Details and registration at momath.org/hyperboloids/
A hyperboloid of one sheet made out of wooden skewers next to Mae West, an enormous sculpture of a hyperboloid of one sheet in Munich. Next to the wooden skewers hyperboloid is written “This one doesn’t exist”.
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John Golden @johngolden.bsky.social · 17/07/2026
#rationalcats what should they name the kitten?
Two parents with a kitten. Parents are labeled 2/3 and 3/5, kitten with a ?.
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Dr. Emily Friedman @ecfriedman.com · 17/08/2026
I don’t yet know if this is my new bestie or hilarious campus nemesis. (But seriously, this is cool and I want my next university headshots here)
wire.auburn.edu
COSAM lecturer's dice design solves board gaming's most surprisingly complex problem — who goes first?
A simple question about who goes first turned into a 15-year mathematical puzzle. Auburn COSAM senior lecturer Eric Harshbarger and researchers around the world developed a set of dice that eliminates...
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Pam Harris @pwharris.bsky.social · 13/08/2026
#TryThisThursday Rather than stressing why one doesn't belong, emphasize what the other three have in common. Discussion is key! Do it for each quadrant! #MathIsFigureOutAble #MTBoS #ITeachMath #MathEd
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Grant @syncingsinking.bsky.social · 13/08/2026
New academic year so a good time to reskeet the #MathSky starter packs! go.bsky.app/66Us7WW
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Joshua Bowman @thalesdisciple.bsky.social · 05/08/2026
With the end of the summer approaching, as I am preparing for my fall classes, I found this note I wrote to myself back in June. Good job, me.
What I want my classes to be

Affirming
• of one's capacity to do mathematics
• of one's worth as a human being

Inspiring
• aesthetically: mathematics is a beautiful subject
• scientifically: mathematics is a powerful subject

Challenging
• push students to do harder work
• create productive shifts in how to understand and analyze the world

Forward-looking
• providing a pragmatic basis for future study
• directed to an open-ended view of the subject

Collaborative
• catalyzes earlier properties
• builds social skills
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Jenna Laib @jennalaib.bsky.social · 31/07/2026
NEW BLOG POST Nmbr 9: Opportunities to Observe and Nudge Student Thinking While Playing Games What a commercial game (Nmbr 9) revealed about my daughter's mathematical thinking — and how playing "just for fun" led us into a larger mathematical conversation. Link below:
jennalaib.com
Nmbr 9: Opportunities to Observe and Nudge Thinking While Playing Games
During the school year, I spend time thinking about math games for the classroom. Most often, I'm thinking content first. I adapt games with structures I love, like Number Boxes, to highlight different ideas or flex different skills. These games serve many purposes -- learn more about student thinking, develop mathematical reasoning and strategies, exercise social skills -- but the primary function is curricular.
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Amie Albrecht @nomadpenguin.bsky.social · 28/07/2026
Hot off the heels of my last blog post, I read the coverage of last week's Fields Medallists. As usual, I wasn't looking for what they had done, but how they had done it. Read here: amiealbrecht.com/2026/07/28/play-is…
amiealbrecht.com
Play is not the opposite of ambition
I read the coverage of last week’s Fields Medallists, looking to understand how they work.
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Amie Albrecht @nomadpenguin.bsky.social · 23/07/2026
You aren't imagining things. After more than 18 months, it's a new post on my blog! Are play and work really opposites? I read Dewey's century-old chapter 'Play and Work in the Curriculum'. The answer may not surprise you … amiealbrecht.com/2026/07/23/dewey-o…
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John Golden @johngolden.bsky.social · 19/07/2026
Blog post about a lesson I loved this week, inspired by graphing stories mathhombre.blogspot.com/2026/07/math... #iteachmath
mathhombre.blogspot.com
Math Performances
I'm teaching a summer algebra course for incoming students. It's our intermediate algebra course stretched to two semesters, my first time ...
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NCTM @nctm.org · 06/07/2026
⏰Starting next week: The highly anticipated MTLT Virtual Writing Boot Camp! ️Participate in an intense, one-week writing experience that will support you toward publication in MTLT. Sign up here: nctm.link/VQ6bF
Virtual Writing Boot Camp scheduled for July 13–17, 2026, with a textured blue background and bold white and yellow text.
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DavidPetro314 @davidpetro314.bsky.social · 06/07/2026
[New Post] Ontario Math Links - My favourite #math links from this week: ontariomath.blogspot.com/2026/07/math... Links and help from @davidkbutler.bsky.social @howiehua.bsky.social @transum.bsky.social @camatsumoto10.bsky.social @teacher2teacher.bsky.social and more #MathChat #MTBoS #iTeachMath
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Adrienne Hestenes @ahestenes.bsky.social · 30/06/2026
I won’t be at Bridges Math conference, but my hand embroidered Lorenz Attractor will be! #ThreadedTheorems used my photo in their paper. Yay! I see @samjshah.bsky.social has his embroidered aperiodic monotile in this paper as well. #mtbos archive.bridgesmathart.org/2026/bridges...
archive.bridgesmathart.org
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Fractal Kitty @fractalkitty.com · 29/06/2026
A new post on a puzzle coming out in a puzzle book from Natural Math. www.fractalkitty.com/moduloku/ @maria-naturalmath.bsky.social #mtbos #modulo #puzzle #moduloku #recurseCenter
fractalkitty.com
Moduloku
Math is wonderful, and there are so many different ways to play and experience it. I enjoy having conversations with other math lovers and sharing ideas, puzzles, pedagogy, and questions. In one of t...
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Joseph O'Rourke @josephorourke.bsky.social · 27/06/2026
An unsolved problem. Given an m×n map formed of unit squares, with a given Mountain/Valley assignment for every crease, is there a subexponential algorithm to decide if it can be folded to a 1×1 stack of squares? Example: Yes. #MathSky #Mathematics #Geometry #Origami 🧪 cs.smith.edu/~jorourke/Ma...
2x4 map to fold to 1x1
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Harry Zafar @harryzafar.bsky.social · 27/06/2026
Saw something recently about AI making an incorrect quadratic graph. Gave me an idea to use AI to create "common sense" check questions. Students often don't check if their answer makes sense. I try to embed this in my teaching, this will help. Started with quadratics #mathstoday shorturl.at/Y7jfq
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robertfathauer.bsky.social @robertfathauer.bsky.social · 25/06/2026
The website for the 2026 Bridges Conference Exhibition of Mathematical Art, Craft, and Design is now live, featuring the work of more than 150 artists. gallery.bridgesmathart.org/exhibitions/...
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Danielle @ PixiMaths @piximaths.bsky.social · 26/06/2026
I got carried away and made a thing... Testers welcome! #alevelmaths #mathstoday #alevelrevision #mathsrevision
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Stuart @sxpmaths.bsky.social · 24/06/2026
The more you stare at this, the worse it gets. Going to ask students how many faults they can find with it!
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Pierre Tranchemontagne @pierretranche.bsky.social · 21/06/2026
I finally took some time to add submitted images to the Number Talk Images website. Check them out on the Photos page. ntimages.weebly.com
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The MEaSURE Project @themeasureproject.bsky.social · 21/06/2026
Doing a test experiment on today's solstice...results to follow!
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UK Maths Trust @ukmathstrust.bsky.social · 26/03/2026
Problem of the Week 165! Please do not comment the solution so others can work it out too. Instead, like this post or comment a thumbs up if you think you have the correct answer! The solution will be posted in the comments on Thursday afternoon. #Problem #UKMT #Maths
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Erick Lee @theericklee.bsky.social · 20/06/2026
A #MathArt project with my #calculus class! A "Riemondrian" art project inspired by @mathzorro.bsky.social. Students used a Riemann Sum to approximate the area under their curve. Then created additional blocks of color using custom color palettes (this one is "Moon Mist"). #ITeachMath #MathsToday
A geometric Desmos graph depicting a Riemann sum with a Piet Mondrian abstract art aesthetic. A thick, vibrant coral-pink cubic function curve waves smoothly from left to right across the square frame. The graph is filled with a grid of rectangular blocks using a "Moon Mist" ice cream color palette: grape purple, banana yellow, bubblegum blue, and crisp white. The colorful blocks form vertical columns bounded by clean, dark teal lines, abstractly representing the calculus area approximation underneath the pink curve.
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Justin Lanier @jlanier.bsky.social · 19/06/2026
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...
A 4x4 puzzle grid, indicating an example of an alternating sign matrix; an example of a configuration of 21 points that maximized the number of pairs that are a unit distance apart. These are the two mathematical themes of the 2026 program.
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Erick Lee @theericklee.bsky.social · 19/06/2026
A couple of questions for the final day of my #calculus class. The hexagon question was from a post at the other place by Henk Reuling. I added the square version as a simplified option. #ITeachMath #MathsToday
Two calculus challenges side by side, framed in rounded blue borders. On the left side, labeled Mild, a text prompt asks, A parabola is drawn inside a square. What fraction of the square is colored red? Below the text is a square containing a bright red vertical parabola whose peak touches the top edge midpoint and whose base spans the bottom corners from edge to edge. On the right side, labeled Spicy, a text prompt asks, A parabola is drawn inside a regular hexagon. What fraction of the hexagon is colored red? Below the text is a regular hexagon resting on a flat bottom edge, containing a tall red vertical parabola whose peak touches the midpoint of the top edge and whose base spans the bottom edge from corner to corner. For both challenges, the areas inside the shapes but outside the red parabolas are shaded light grey.
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Desmos Studio @desmos.com · 18/06/2026
Are you ready to share that Desmos notebook you've been working on? Learn more about logging in, saving, and previewing your work. What question should we answer next? #mathsky #iteachmath
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Terry Matz @terrymatz.bsky.social · 17/06/2026
Happy Birthday to M. C. Escher born on June 17, 1898. It's also World Tessellation Day in honor of Escher's iconic tiling and morphing art. 🧶 Celebrate with knitting patterns inspired by Escher's artwork like these on my tessellation knitting post intheloopknitting.com/escher-knitt...
Collage of knitting projects: 
1. A sweater inspired by M. C. Escher’s woodcut Sky and Water I of fish morphing into birds. Designed by Sylvie Odstrčilová. Pictured project by Saskibla
2. Two people holding a knit blanket of tessellated seahorses, inspired by Escher's Seahorses No. 88. Designed by Beverly Simmons.
3. A closeup detail of On the Shore Blanket inspired by Escher's Fish, Duck, Turtle Symmetry Drawing No. 69. Designed by Jana Huck
4. Duck Sweater 609 of interlocking graphic ducks in various colors. Designed by Lucy Neatby.
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Daniel Wilson @helsig.bsky.social · 17/06/2026
#MathArt
A tiling.
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Erick Lee @theericklee.bsky.social · 14/06/2026
Tomorrow starts off the last week of my #calculus class. We're starting with this question from @paddymacmahon.com. I'll be interested to see how my students approach the second question. #ITeachMath #MathsToday
Two side-by-side math problems labeled "MILD" and "SPICY" with chili pepper icons, focusing on calculus integration in the first quadrant.

Left Panel (MILD):

Text prompt: "Find the area in the first quadrant between the two functions."

Graph details: Shows an x-y coordinate plane. A red downward-opening parabola is labeled "y = 4 - x^2". A green straight line is labeled "y = -2x + 5" and is tangent to the parabola in the first quadrant. The area between the line and the parabola, bounded by the y-axis on the left and the x-axis on the bottom, is shaded green.

Right Panel (SPICY):

Text prompt: "What value of a minimizes the area in the first quadrant between the parabola and its tangent line."

Graph details: Shows the same red downward-opening parabola labeled "y = 4 - x^2". A blue tangent line touches the parabola at a point where the x-axis value is marked as "a" with a vertical dashed line. The region between the tangent line, the parabola, the y-axis, and the x-axis is shaded blue-green.
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Mark McCourt @markmccourt.bsky.social · 14/06/2026
NEW BLOG: Retrieval Is Not a Starter Activity www.emaths.co.uk/blog/general...
Illustrated blog banner for an education article titled Retrieval Is Not a Starter Activity. A teacher leads a discussion with pupils while a mathematical problem involving trigonometry is displayed on a whiteboard. The scene emphasises the use of prior knowledge to solve new problems, with visual references to retrieval, method selection, connection-making and application. The design conveys the idea that retrieval is most powerful when embedded naturally within the story of learning rather than used as a disconnected classroom routine.
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Darth Calculus 🏳️‍🌈 @darthcalculus.bsky.social · 11/06/2026
Here's a #Desmos notebook I made to support one of my Algebra 2 lessons next September. I think these will be really useful as "digital manipulatives" that students can play with to build intuition. #EduSky #ITeachMath www.desmos.com/notebook/sya...
desmos.com
1-5 Writing Linear Equations
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Ralph Pantozzi @mathillustrated.bsky.social · 12/06/2026
Let’s suppose you had 7 minutes to address the Modernizing Math Education 9-14 committee. What would you want them to know? #iTeachMath Agenda for June 23: www.nationalacademies.org/cdn/material... Note: only a few on the committee have teaching experience in 9-12, and it’s not recent.
nationalacademies.org
Modernizing Mathematics Education for Grades 9-14
A student’s mathematical education can help advance their future goals for daily life, education, and career, or this experience can pose a significant obstacle to their progress. A consensus committe...
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Erick Lee @theericklee.bsky.social · 10/06/2026
Did a few review questions as a class with my #calculus students from www.mathmatize.com. A nice way to start the period. Then I gave them a few to try on their own at home. #ITeachMath #MathsToday @mathmatize.bsky.social
An online calculus practice question from mathmatize.com.

The problem statement reads: "The region enclosed by y = (x^2)/4 and y = 5 - x^2 is rotated about the x-axis. Fill in the blanks to correctly compute the volume of the resulting solid:"

Below the text is an incomplete integral formula:
Volume = Integral from [dashed blank] to [blank] of [blank] dx

At the bottom, a multiple-choice interface for "Blank 1" shows a row of selectable numerical buttons: -4, -2, -1, -1/2, 0, 1, 1/2, 2, and 4. A purple button below reads "CHECK ANSWER" with "3 attempts remain" written underneath.
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Erick Lee @theericklee.bsky.social · 10/06/2026
Perfect symmetry! Solved today’s All Ten puzzle with all expressions using the digits 6, 2, 2, 1 in the same order. #ITeachMath beastacademy.com/puzzles/dail...
An All Ten puzzle where every number is made with digits in the same order.
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Erick Lee @theericklee.bsky.social · 09/06/2026
Did this as a warm-up with my #calculus class today. Some nice discussions, especially regarding area #3. Also asked them to think about the volume of area #4 rotated around the x-axis. #ITeachMath #MathsToday @mrlevmaths.bsky.social
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Erick Lee @theericklee.bsky.social · 09/06/2026
We didn't have power all afternoon at school. Luckily, you don't need power to arrange these definite integral dominos into a circle. A great way to start #calculus class. Thanks for sharing @math-problems.bsky.social! #ITeachMath #MathsToday
Students are arranging calculus domino-style cards into a long, winding chain. Each card is divided in half: one side features a definite integral formula, and the other side shows either a numerical answer or a shaded graph representing the area under a curve.A completed chain of twelve domino-style cards arranged in a circle. Each card is divided in half: one side features a definite integral formula, and the other side shows either a numerical answer or a shaded graph representing the area under a curve.
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