Tag Archives: The Geometer’s Sketchpad

Thanks, @seidelj! Currently exploring Cardioid activities using either Geometer’s Sketchpad or pencil/paper. #mathchat #STEAM #STEMed #ValentinesDay #NYCISTk6

Screen Shot 2018-02-13 at 9.57.26 AMLast week, I bumped into Judith Seidel (@seidelj) at a lecture at the Museum of Mathematics. She suggested I explore a Cardioid Activity on Geometer’s Sketchpad  — and just in time for Valentine’s Day too! A quick Google search yielded these resources which I forwarded to the Math Department:

1. A Geometer’s Sketchpad lesson plan:

2. A video tutorial with doable paper/pencil/ruler instructions:

3. More information about cardioids and the math behind them:

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Fractals in 6th Math with @kkleinNYC, Geometer’s #Sketchpad, @Scratch, and pencils. @The_School #mathchat

I’ve had a deep love and respect for Geometer’s Sketchpad since I was first introduced to it in 1994 as an undergraduate Math major (and aspiring math teacher) at Bryn Mawr College.

Later, I used Geometer’s Sketchpad during my student teaching stint at Strath Haven High School and again as a pre-Algebra/pre-Geometry teacher at The Dalton School.

Today in 6th grade Math at The School at Columbia University, Katie Klein (@KKleinNYC) and her associate teacher, Jazmin Sherwood, facilitated a great lesson on Fractals blending direct instruction, video, and self-paced sketching with and without technology.

1. Homework from the previous night was to watch the first 20 minutes of Fractals, Exploring the Hidden Dimension.

2. Here’s a link to beautiful photos of fractals found in nature:  http://io9.com/incredible-photographs-of-fractals-found-in-the-natural-480626285

3. Here are instructions for drawing Sierpinski Triangles with paper and pencil:

4. Here are instructions for drawing Sierpinksi Triangles using Geometer’s Sketchpad on their laptops:

5. Here’s another resource for making other fractals with Geometer’s Sketchpad:  http://www.gwinnett.k12.ga.us/PhoenixHS/math/GSP-website/17_Fractals(51-61).pdf

6. With additional time, students could explore fractals with Scratch or Snap (both are web-based block-based programming environments). Here are some links I gathered:

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Playing with the #SketchpadExplorer app. Download it for free until 11/1/11 via @keypress

Daniel Scher is a principal investigator for The Dynamic Number Project. He works to create the iPad-compatible constructions for the Sketchpad Explorer app. Sketchpad Explorer is the iPad companion to Geometer’s Sketchpad software program – both are published by Key Curriculum Press (@keypress on Twitter).

Daniel will be coming to The School at Columbia University to help me help the 5th grade teachers integrate Sketchpad Explorer into their math curriculum. He’s psyched to watch/evalutate how kids learn with the app versus the software versus without either, and I’m excited to get a full grade of teachers to use a tool that I consider to be an industry standard for math educators. I love Geometer’s Sketchpad, and I recently gushed about Sketchpad Explorer on Scholastic’s Best in Tech Today.

Upon opening the Sketchpad Explorer app, there is an animated proof of the Pythagorian Theorem.


On the bottom right corner is a book icon. This takes you to many options, one of which is to visit the Sketch Exchange community site. From here, you can click Sketch Exchange sketches tagged with ipad, and then you can choose dynamic numberin the tag cloud. These sketches open up with the full Geometer’s Sketchpad software program as well.


There are four pages of sketches to choose from. I initially chose Balance Scale: Solving for Unknowns Part 1. When you choose a sketch, further down the page you’ll find links to download activity notes, worksheets, and the actual sketch with the .gsp suffix. I was super excited to note the CreativeCommons license (!) of Attribution Non-Commercial No Derivativeswhich translates to: Give me credit, don’t make money off it, and don’t alter it. I love Creative Commons almost as much as Geometer’s Sketchpad. 🙂


I had a bit of fun playing with this screen trying to figure out the value of the star and other shapes using the fulcrum, and yes, I think I’m smarter than a 5th grader.


Download the Sketchpad Explorer app here: http://itunes.apple.com/us/app/sketchpad-explorer/id452811793?mt=8

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