Author: Scott Steketee

Dilation Games: Assessment That’s Fun

March 2023 UPDATE: If the dilation games below whet your appetite for challenges based on transformations, check out these Reflection and Rotation games as well. What does dilation feel like? I recently had the opportunity to work with a group of students who were testing activities that treat geometric transformations as functions (what I call geometric...

Hello Spring!

Today’s blog post features a sketch from Anna Nguyen, who’s a 9th grade student. Anna observes, “Math is one of my favorite subjects. I’m not a genius or the smartest in my class, but I do enjoy dealing with letters and numbers, which is also why I like chemistry. I think GSP is the most...

Constructing Morley Triangles

By Adrienne Barrett This post is by guest blogger Adrienne Barrett, who’s a senior mathematics and education dual major at Rowan University. She is currently student teaching and upon graduation in May, she hopes to find a full-time position teaching high-school mathematics. She’s always loved math, and studying it in college has given her a...

Pi Day 2015: Pieces of Pi

For this year’s Pi Day post, I thought I’d continue our Web Sketchpad (WSP) construction theme. But rather than adapting the visualizations from last year’s Pi Day post to the new construction capabilities, I decided to take a different approach. Some time ago, I built a set of custom tools for the non-Web version of...

Tribute to Zalman Usiskin

On November 6 I had the honor of being one of the panelists in a Symposium Honoring Zalman Usiskin, held to honor Zal’s many years of contributions to mathematics education, from his groundbreaking 1971 textbook Geometry: A Transformation Approach (GATA) to his continuing activities today. My panel was supposed to discuss his work on the...

Pentaflake Chaos

Dan Anderson commented on my Pentaflake post to observe that the pentaflake can also be created by a random process, sometimes called the Chaos Game. In this game you start with an arbitrary point and dilate it toward a target point that’s randomly chosen from some set of points that you’ve established. You then dilate...

How do you make … a pentaflake?

A couple of days ago I got an email from my long-time friend Geri, who was spending some quality Sketchpad time with her 12-year-old grandson Niels. Geri emailed me for advice because Neils was having some trouble figuring out how to construct a pentaflake. Neither Geri nor Niels had any idea that I’d never even...

Dilation Challenges

For a while now, I’ve been intrigued by the ways in which the study of geometric transformations can provide students with a very effective introduction to function concepts. Daniel and I have written a couple of articles about this topic, and we created a number of activities to take advantage of what can arguably be...