Tessera

It’s always hot in Phoenix, but it’s definitely getting hotter. #ShowYourStripes showyourstripes.info/l/northameri...

Show Your Stripes

Visualising how the climate has changed for every country across the globe

showyourstripes.info

Justin Lanier@jlanier.bsky.social · 2mo ago

I participated last summer and it really energized me. So great to work problems with others, and to hear from mathematicians about their work. I will definitely be attending again. Two thumbs up! #iTeachMath #MTBoS #MathsToday

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.

After the #IllustratingMath seminar online this morning, I've been thinking about Ford Circles (new to me). I was messing around with plotting the circles, and found I could get quadratic equations to go through the center of circles tangent to circle 1. (1/n) www.desmos.com/calculator/5...

Ford Circles

desmos.com

I impulse bought this book, and I have no regrets. #iTeachMath

Photo shows the book cover of “99 Variations on a Proof” by Philip Ording. The image on the book cover is a 10 by 10 square grid with the top left corner removed, showing 99 squares.

Hey #MTBoS ! This book is great. If you want fresh ideas for your #MathCircle or math club, or have an interest in unique and surprising problems, I whole heartedly recommend this. share.google/3xFifOEa4EAb...

Five Fabulous Activities for Your Math Circle - Natural Math

Five Fabulous Activities for Your Math Circle is a guidebook for teachers, parents, and math circle leaders. The book is primarily for those working with middle and high school students, with some act...

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Raj Raizada@rajraizada.bsky.social · 3mo ago

Off to try this out! This looks awesome. #iTeachMath #desmos #mtbos

Your dream came true today!! youtu.be/Lv0MRBIeBTE?...

I didn’t feel like I connected with my students as well this year. Then #inMathsToday a student handed me a thank you letter on her way out. It was a full handwritten page describing her positive experience with the class. I was floored and had no idea my impact on her. This letter is a keeper!

I got some Hypertiles and am looking for ways to use them in Multivariable Calculus. I’m thinking about having students drawing cross sections or level curves for a particular construction. Anyone have other ideas? #iTeachMath #MTBoS

A Hypertiles is in the shape of a hyperboloid of one sheet showing the saddle point. In this photo, 3 have been connected with linkages to make a sort of wavy triangular shape with a peak in the middle.

A side view of the model described in the other photo. The Hypertiles are sitting on a desk in a classroom with clean whiteboards in the background. The shape shows the vertices of the triangular shape curving upwards while the sides of the triangle curve downwards. The center where all 3 tiles meet is curving upwards.

Comparing the circular motion of 2 large Ferris wheels in #MathsToday .

Student whiteboard work showing sketches of Ferris wheels with dimensions labeled. Next to them are the graphs of a person’s height as the wheel turns along with equations.

Adrienne Hestenes @ahestenes.bsky.social · 4mo ago

I was pursuing @theericklee.bsky.social math blog today and it is full of great ideas that can scale up or down on grade level. Go check it out! #iTeachMath pbbmath.weebly.com

Blog

I start each of my calculus classes with a short warm-up question. I use a broad mix of different types of questions and routines depending on what is needed that day. Some are a quick mental math...

pbbmath.weebly.com

Ocotillo on my walk today. #nature #walk #sky #Arizona

A photo of Ocotillo in bloom. Looking up towards the sky. Ocotillo is covered in small green leaves and the ends have the bright red cone shaped flowers. Some flowers are not open yet and appear as yellow buds.

Adrienne Hestenes @ahestenes.bsky.social · 5mo ago

I’ve got some students working on the pidaychallenge.com this weekend. They are having fun. I don’t know who makes this, but kudos to them! #MathsToday. ♾️

Pi Day Challenge

pidaychallenge.com | Pi Day Challenge

pidaychallenge.com

Adrienne Hestenes @ahestenes.bsky.social · 5mo ago

I just volunteered my students to puzzle test for this. I loved thee big yellow game book he did. #MTBoS

John Golden@johngolden.bsky.social · 5mo ago

Great opportunity from Ben Orlin. mathwithbaddrawings.com/2026/03/11/p... I loved playtesting for his #mathgame book. Guessing the puzzles will also be such fun!

Vector fields as art. In #MathsToday the students had to create a vector field and overlay it with a picture to create Vector Art. Just a fun little extension at the end of a unit. #iTeachMath

Image is a subsection of Van Goghs Starry Night. It’s the large whorl in the sky. Over the image is a vector field which points along the whorl. The vector field is -sin(x-y) for the i component and cos(x+y) for the j component. The vector field is handwritten. The image is black and white.

The vector field F=<x,2-x^2> is overlayed on the image of a fountain in a pond. The water sprays straight up and falls down into a circular region. The vectors point along the motion of the water.

OMG I won! www.mscroggs.co.uk/blog/122

Christmas (2025) is over

Welcome to 2026 everyone! It's time to reveal the answers to the Advent Calendar puzzles and announce the winners. But first, some good news: with your help, Santa was able to order a new sleigh and C...

mscroggs.co.uk

In #MathsToday we had success discovering the log properties. I had students use a log table to find all the ways to combine logs to equal log2, which led to them noticing the loga-logb=log(a/b) property. Then they looked for ways to make log12 (which led to discovering the product property.

In #MathsToday we used the Koch Snowflake to review writing exponential equations from data. Students then discussed what the end behavior would be for the equation of the perimeter. The kids enjoyed hearing how this was thought “abominable” by mathematicians when first discovered.

Student whiteboard work which shows an attempt at drawing the Koch snowflake. Start with a triangle, divide each sides into thirds, and replace the middle third with a new equilateral triangle, then repeat. Below the Koch Curve is a table which records the number of sides in column one, the length of a side in column 2, and the third column will hold the perimeter, but is currently empty. The rows represent the iteration. Below the table the students are working on are some multiplication calculations.

Student white board work shows a table with the following columns; stage number, number of sides, side lengths, and perimeter. The stage nUmber column contains 0, 1,2,3,n. The number of sides column contains 3,12,48,192 and the function 3(4^n). The side lengths column contains 1,1/3,1/9,1/27, and the function 1/3^n. The perimeter column contains 3,4,48/9,7 (sic), and the function 3(4^x)/(3^n).

In #MathsToday we learned how to sketch vector fields. Then we had some fun with this neat app. Try the randomize button. #maths #MathArt anvaka.github.io/fieldplay/?c...

Vector Fields, Math and Art.

This website allows you to build and explore beautiful world of vector fields.

anvaka.github.io

I’m going to #TCM in North Carolina in February! Super excited. All the abstracts look great. But I know for sure I want to attend the Knot Coloring and systems of equations talk. Anyone else attending? #MTBoS

In #MathsToday we started with a menu task. Students had to write as few quadratic equations (in vertex form) as possible while hitting 10 constraints. Enjoyed watching students explain their thinking to each other.

This photo shows the arm of a student writing on a whiteboard. The work shows some quadratic equations in vertex form, some sketches of the equations, and some student notes about which constraints can or cannot pair together.

Teachers who participated in @jlanier.bsky.social Twenty-first century mathematics workshop last summer might be interested in the monthly seminars hosted by @chalkdustmag.bsky.social by authors of papers in the book. #iTeachMath #MTBoS chalkdustmagazine.com/blog/theorem...

Theorems of the 21st Century Seminar - Chalkdust

A new online seminar series. Each seminar is an accessible introduction to a theorem of the 21st century.

chalkdustmagazine.com

In #MathsToday I had all the students at the whiteboards and asked them to solve ax^2+bx+c=0 by completing the square. They were so surprised to get the quadratic formula as their answer, and then they were proud they had derived this mystical formula without even realizing they were doing it.

a heart with the words " quadratic formula my beloved " written on it

Alt: a heart gif opens up with the words " quadratic formula my beloved " written on it

media.tenor.com

Catriona Agg@catrionaagg.bsky.social · 7mo ago

Something that went well in #MathsToday was a personal victory for me. I’ve been trying to draw a particular student out, and today she volunteered to share her unique approach to solving a quadratic visual pattern. It’s always wonderful when the quiet voices speak up. 👍

By the way, why not make your New Year’s resolution be to start sharing little things that went well in your maths lessons using #MathsToday? Whenever I make a habit of this, it always makes me feel more positive about my job. It’s lovely to scroll through and see what everyone else is doing too.

Completing squares in #MathsToday and came to learn not a single student in class had ever used algebra tiles. Thank goodness for polypad! Quickly had students geometrically completing the square. You can even cut the algebra tiles in half and solve problems with fractions.