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 functions). I got lots of good ideas for improving the activities not only by watching the students, but also but also from their suggestions … Continue Reading ››

In a prior blog post, I described the pins-and-string approach to drawing an ellipse: Press two pins into a corkboard, place a loop of string around the pins, pull the string tight with a pencil, and trace the pencil tip's path as you pull the pencil around the taut string. Guaranteeing that the traced … Continue Reading ››

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 … Continue Reading ››

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 … Continue Reading ››

Today there is no lack of outrage directed at the high-stakes standardized testing that has become so prevalent in the U.S. educational system. A recent opinion piece in The New York Times examines the backlash against the Common Core and lays the blame not on the standards themselves, but rather … Continue Reading ››

In my previous post, I shared Dan Meyer's analysis of what's wrong with computer-based mathematics assessments. Dan focuses his critique on the Khan Academy's eighth-grade online mathematics course, identifying 74% of its assessment questions as focusing on numerical answers or multiple-choice items. This is … Continue Reading ››

I first encountered the kinetic sculptures of Arthur Ganson nearly 20 years ago at the MIT Museum. Ganson is an engineer, artist, and inventor whose machines, when set in motion, display a grace you would not expect from metal, gears, and other industrial objects. Below is a video of one of … Continue Reading ››

Tomoko Fuse is a Japanese origami artist whose designs are highly geometric. A Google search for her origami models reveals a plethora of boxes and intricate three-dimensional structures, many of which are folded from multiple sheets of … Continue Reading ››

In a recent blog post, Karen Greenhaus describes how it's possible to construct familiar corporate logos using Sketchpad. You might start with a rhombus, for example, and then reflect it twice to … Continue Reading ››