Shaun Errichiello
@shaunteaches.bsky.social
I teach math and I am excited about it!!!
My students are making some stunning parametric and polar art. To help them, I share the wonderful website mathcurves and was pleasantly surprised when a student used a fish curve to make a fish. How cool is this curve?
mathcurve.com/courbes2d.gb...
#precalc #iteachmath #iteach #fish #parametric
mathcurve.com/courbes2d.gb...
#precalc #iteachmath #iteach #fish #parametric
January 22, 2026 at 5:18 PM
My students are making some stunning parametric and polar art. To help them, I share the wonderful website mathcurves and was pleasantly surprised when a student used a fish curve to make a fish. How cool is this curve?
mathcurve.com/courbes2d.gb...
#precalc #iteachmath #iteach #fish #parametric
mathcurve.com/courbes2d.gb...
#precalc #iteachmath #iteach #fish #parametric
Math teaching prep highlight: having blue and red colored math expressions combine and mix to purple!
…I spend too much time on this stuff, but I share the intent with students and it makes them laugh.
#iteachmath
#edusky
#mathsky
…I spend too much time on this stuff, but I share the intent with students and it makes them laugh.
#iteachmath
#edusky
#mathsky
December 17, 2025 at 3:16 PM
Math teaching prep highlight: having blue and red colored math expressions combine and mix to purple!
…I spend too much time on this stuff, but I share the intent with students and it makes them laugh.
#iteachmath
#edusky
#mathsky
…I spend too much time on this stuff, but I share the intent with students and it makes them laugh.
#iteachmath
#edusky
#mathsky
Any thoughts on a precalculus spirograph project? I'd love to start working on one!
#mtbos
#iteachmath
#mathsky
#edusky
#mtbos
#iteachmath
#mathsky
#edusky
December 16, 2025 at 3:38 AM
Any thoughts on a precalculus spirograph project? I'd love to start working on one!
#mtbos
#iteachmath
#mathsky
#edusky
#mtbos
#iteachmath
#mathsky
#edusky
Tomorrow, I get to help students analyze epicycloids and hypocycloids! Here we come spirographs! I am including the graphs they get for reference (I had fun making them on Desmos!)
epi: www.desmos.com/calculator/j...
hypo: www.desmos.com/calculator/f...
#desmos
#iteachmath
#mathsky
epi: www.desmos.com/calculator/j...
hypo: www.desmos.com/calculator/f...
#desmos
#iteachmath
#mathsky
Epicycloid Grapher
www.desmos.com
December 16, 2025 at 3:36 AM
Tomorrow, I get to help students analyze epicycloids and hypocycloids! Here we come spirographs! I am including the graphs they get for reference (I had fun making them on Desmos!)
epi: www.desmos.com/calculator/j...
hypo: www.desmos.com/calculator/f...
#desmos
#iteachmath
#mathsky
epi: www.desmos.com/calculator/j...
hypo: www.desmos.com/calculator/f...
#desmos
#iteachmath
#mathsky
Polygonal sine waves. I love this and am excited to show it to students. It helps students recognize that the trig we cover in school is just the beginning.
#iteachmath
#edusky
#mtbos
www.tumblr.com/1ucasvb/4288...
#iteachmath
#edusky
#mtbos
www.tumblr.com/1ucasvb/4288...
Post by @1ucasvb · 1 image
💬 5 🔁 302044 ❤️ 207518 · The familiar trigonometric functions can be geometrically derived from a circle.
But what if, instead of the circle, we used a regular polygon?
In this animation, we se…
www.tumblr.com
December 9, 2025 at 1:02 PM
Polygonal sine waves. I love this and am excited to show it to students. It helps students recognize that the trig we cover in school is just the beginning.
#iteachmath
#edusky
#mtbos
www.tumblr.com/1ucasvb/4288...
#iteachmath
#edusky
#mtbos
www.tumblr.com/1ucasvb/4288...
Tried the prompt below before showing sinusoids in a Ruben's tube. Then we watched this quick video: youtu.be/_8KjE7MQHXM?...
I want to convince students that anything that oscillates might be modeled with a sinusoid. They are everywhere!
#mtbos
#iteachmath
#edusky
#mathsky
I want to convince students that anything that oscillates might be modeled with a sinusoid. They are everywhere!
#mtbos
#iteachmath
#edusky
#mathsky
November 25, 2025 at 12:12 AM
Tried the prompt below before showing sinusoids in a Ruben's tube. Then we watched this quick video: youtu.be/_8KjE7MQHXM?...
I want to convince students that anything that oscillates might be modeled with a sinusoid. They are everywhere!
#mtbos
#iteachmath
#edusky
#mathsky
I want to convince students that anything that oscillates might be modeled with a sinusoid. They are everywhere!
#mtbos
#iteachmath
#edusky
#mathsky
I posted this a while ago, but this is still my favorite way to prove the addition identities for trig. What are your favorite approaches?
#MtBos
#MathSky
#IteachMath
#MtBos
#MathSky
#IteachMath
November 21, 2025 at 4:26 AM
I posted this a while ago, but this is still my favorite way to prove the addition identities for trig. What are your favorite approaches?
#MtBos
#MathSky
#IteachMath
#MtBos
#MathSky
#IteachMath
Exploring Islamic Constructions in Geometry and am considering incorporating Geogebra!
Here is the 12-pointed star with a focus on dynamic color. Thinking about what else students might like to do!
#Mathsky
#iTeachMath
#Geogebra
www.geogebra.org/m/vngxfcfy
Here is the 12-pointed star with a focus on dynamic color. Thinking about what else students might like to do!
#Mathsky
#iTeachMath
#Geogebra
www.geogebra.org/m/vngxfcfy
12-Pointed Star
12-Pointed Star
www.geogebra.org
November 20, 2025 at 3:07 AM
Exploring Islamic Constructions in Geometry and am considering incorporating Geogebra!
Here is the 12-pointed star with a focus on dynamic color. Thinking about what else students might like to do!
#Mathsky
#iTeachMath
#Geogebra
www.geogebra.org/m/vngxfcfy
Here is the 12-pointed star with a focus on dynamic color. Thinking about what else students might like to do!
#Mathsky
#iTeachMath
#Geogebra
www.geogebra.org/m/vngxfcfy
I love spinning the functions around the unit circle! I will show this one in class and find it relaxing to watch. The only question is, what song should I play as we spin the circle?
#iteachmath
#mathsky
#MtBoS
Video: www.youtube.com/watch?v=ASC2... Graph: www.geogebra.org/m/kutagxpj
#iteachmath
#mathsky
#MtBoS
Video: www.youtube.com/watch?v=ASC2... Graph: www.geogebra.org/m/kutagxpj
All six trig functions on a unit circle
YouTube video by shaunteaches
www.youtube.com
November 18, 2025 at 4:19 AM
I love spinning the functions around the unit circle! I will show this one in class and find it relaxing to watch. The only question is, what song should I play as we spin the circle?
#iteachmath
#mathsky
#MtBoS
Video: www.youtube.com/watch?v=ASC2... Graph: www.geogebra.org/m/kutagxpj
#iteachmath
#mathsky
#MtBoS
Video: www.youtube.com/watch?v=ASC2... Graph: www.geogebra.org/m/kutagxpj
Teaching trig on the xy plane and “All Students Take Calculus” came up. I’m ready for a new phrase. I’ll have a contest with my students to create their own phrases.
Any ideas?
#iteachmath
#edusky
#MtBoS
#trigonometry
Any ideas?
#iteachmath
#edusky
#MtBoS
#trigonometry
November 12, 2025 at 3:07 PM
Teaching trig on the xy plane and “All Students Take Calculus” came up. I’m ready for a new phrase. I’ll have a contest with my students to create their own phrases.
Any ideas?
#iteachmath
#edusky
#MtBoS
#trigonometry
Any ideas?
#iteachmath
#edusky
#MtBoS
#trigonometry
Anyone else still using chalk? I am one of the last at my high school and love it.
If only I had sliding boards…one can dream.
#hagoromo
#iTeachMath
#MathSky
If only I had sliding boards…one can dream.
#hagoromo
#iTeachMath
#MathSky
November 10, 2025 at 5:14 PM
Anyone else still using chalk? I am one of the last at my high school and love it.
If only I had sliding boards…one can dream.
#hagoromo
#iTeachMath
#MathSky
If only I had sliding boards…one can dream.
#hagoromo
#iTeachMath
#MathSky
Get to teach completing the square tomorrow with a Geometric perspective!
Using this from Jamie Smith
#MtBoS
#ITeachMath
#EduSky
www.geogebra.org/m/kTEjFHJw
Using this from Jamie Smith
#MtBoS
#ITeachMath
#EduSky
www.geogebra.org/m/kTEjFHJw
Completing the Square Visualisation
A simple visualisation tool to help students visualise the process of completing the square and understand the origins of the name of the process.
www.geogebra.org
November 10, 2025 at 1:45 AM
Get to teach completing the square tomorrow with a Geometric perspective!
Using this from Jamie Smith
#MtBoS
#ITeachMath
#EduSky
www.geogebra.org/m/kTEjFHJw
Using this from Jamie Smith
#MtBoS
#ITeachMath
#EduSky
www.geogebra.org/m/kTEjFHJw
Shared this proof of Heron's formula today while playing symphony no. 9. I faded in the steps to the music and then had students discuss the steps. It was fun!
Proof: shorturl.at/VYMT3
Slides: kntn.ly/d34ef3ce
Music: kntn.ly/16e69aa3
#MtBoS
#iTeachMath
#EduSky
Proof: shorturl.at/VYMT3
Slides: kntn.ly/d34ef3ce
Music: kntn.ly/16e69aa3
#MtBoS
#iTeachMath
#EduSky
Dvořák: Symphony №9, "From The New World" - II - Largo
YouTube video by diesillamusicae
www.youtube.com
November 7, 2025 at 3:11 PM
Shared this proof of Heron's formula today while playing symphony no. 9. I faded in the steps to the music and then had students discuss the steps. It was fun!
Proof: shorturl.at/VYMT3
Slides: kntn.ly/d34ef3ce
Music: kntn.ly/16e69aa3
#MtBoS
#iTeachMath
#EduSky
Proof: shorturl.at/VYMT3
Slides: kntn.ly/d34ef3ce
Music: kntn.ly/16e69aa3
#MtBoS
#iTeachMath
#EduSky
Excited to show the Geometry of the difference of squares tomorrow!
I am using this Geogebra graph as a guide:
www.geogebra.org/m/GwA3J77g
#Mtbos
#iTeachMath
#Geogebra
I am using this Geogebra graph as a guide:
www.geogebra.org/m/GwA3J77g
#Mtbos
#iTeachMath
#Geogebra
Difference of Squares
Difference of Squares
www.geogebra.org
November 6, 2025 at 4:01 AM
Excited to show the Geometry of the difference of squares tomorrow!
I am using this Geogebra graph as a guide:
www.geogebra.org/m/GwA3J77g
#Mtbos
#iTeachMath
#Geogebra
I am using this Geogebra graph as a guide:
www.geogebra.org/m/GwA3J77g
#Mtbos
#iTeachMath
#Geogebra
I appreciate that my student has brought Redbull to the AMC math competition. That is dedication. 😀
#Redbull
#iTeachMath
#Redbull
#iTeachMath
November 5, 2025 at 5:55 PM
I appreciate that my student has brought Redbull to the AMC math competition. That is dedication. 😀
#Redbull
#iTeachMath
#Redbull
#iTeachMath
(2/2) When I use paper to track retakes:
1) It encourages conversation. Students come up and sign up. We chat. It’s great.
2) It requires intent. There is something special (still) about signing your name.
3) It’s easy to track and annotate. The binder is right there. I can mark easily.
1) It encourages conversation. Students come up and sign up. We chat. It’s great.
2) It requires intent. There is something special (still) about signing your name.
3) It’s easy to track and annotate. The binder is right there. I can mark easily.
November 4, 2025 at 4:01 AM
(2/2) When I use paper to track retakes:
1) It encourages conversation. Students come up and sign up. We chat. It’s great.
2) It requires intent. There is something special (still) about signing your name.
3) It’s easy to track and annotate. The binder is right there. I can mark easily.
1) It encourages conversation. Students come up and sign up. We chat. It’s great.
2) It requires intent. There is something special (still) about signing your name.
3) It’s easy to track and annotate. The binder is right there. I can mark easily.
(1/2) I spent a long time setting up a digital system for tracking and encourage test retakes. I used it for years, especially since 2020, but this year I went low tech: but paper and a binder. It has been fantastic.
#MathSky
#iTeachMath
#MathSky
#iTeachMath
November 3, 2025 at 10:10 PM
(1/2) I spent a long time setting up a digital system for tracking and encourage test retakes. I used it for years, especially since 2020, but this year I went low tech: but paper and a binder. It has been fantastic.
#MathSky
#iTeachMath
#MathSky
#iTeachMath
(2/2) Seeing students apply their ideas to algorithms is still one of the best aspects of teaching. Here is the student algorithm that I was able to share back with the class today. Sometimes long division is a better choice than synthetic division! Also, these topics rule.
#MathSky #iTeachMath
#MathSky #iTeachMath
October 28, 2025 at 2:02 AM
(2/2) Seeing students apply their ideas to algorithms is still one of the best aspects of teaching. Here is the student algorithm that I was able to share back with the class today. Sometimes long division is a better choice than synthetic division! Also, these topics rule.
#MathSky #iTeachMath
#MathSky #iTeachMath
(1/2) Aren't students amazing? I showed how to use synthetic division to factor a polynomial. The first question I get is about how to avoid synthetic division and use long division! Then I realized I had a similar question three years ago! Here is the original approach:
#MathSky #iTeachMath
#MathSky #iTeachMath
October 28, 2025 at 2:00 AM
(1/2) Aren't students amazing? I showed how to use synthetic division to factor a polynomial. The first question I get is about how to avoid synthetic division and use long division! Then I realized I had a similar question three years ago! Here is the original approach:
#MathSky #iTeachMath
#MathSky #iTeachMath
Found a phone outside a local barbershop. The owner sent their son to get it. He was my student!
We said hello and then I sat down to get my haircut. The barber was also my former student!
Feeling lucky to have made so many connections over the years.
#MathSky
#iTeachMath
We said hello and then I sat down to get my haircut. The barber was also my former student!
Feeling lucky to have made so many connections over the years.
#MathSky
#iTeachMath
loT.mm
March 19, 2025 at 12:53 AM
Found a phone outside a local barbershop. The owner sent their son to get it. He was my student!
We said hello and then I sat down to get my haircut. The barber was also my former student!
Feeling lucky to have made so many connections over the years.
#MathSky
#iTeachMath
We said hello and then I sat down to get my haircut. The barber was also my former student!
Feeling lucky to have made so many connections over the years.
#MathSky
#iTeachMath
Has anyone tried the PicoCalc? It looks cool and I was thinking of trying it out.
www.tomshardware.com/raspberry-pi...
#Mtbos
#iTeachMath
www.tomshardware.com/raspberry-pi...
#Mtbos
#iTeachMath
Raspberry Pi Pico powers $75 PicoCalc portable programming handheld
It may be clockwork, but this is no wind up
www.tomshardware.com
March 15, 2025 at 11:35 PM
Has anyone tried the PicoCalc? It looks cool and I was thinking of trying it out.
www.tomshardware.com/raspberry-pi...
#Mtbos
#iTeachMath
www.tomshardware.com/raspberry-pi...
#Mtbos
#iTeachMath
March 15, 2025 at 2:22 AM
Anyone else getting ads like this?
By the way…I like when kids ask “when will we use this?” It is a great conversation starter!!
#iteachmath #mtbos
By the way…I like when kids ask “when will we use this?” It is a great conversation starter!!
#iteachmath #mtbos
February 12, 2025 at 1:05 AM
Anyone else getting ads like this?
By the way…I like when kids ask “when will we use this?” It is a great conversation starter!!
#iteachmath #mtbos
By the way…I like when kids ask “when will we use this?” It is a great conversation starter!!
#iteachmath #mtbos
December 9, 2024 at 9:46 PM