All posts by Scott Steketee

Scott Steketee taught secondary math and computer science in Philadelphia for 18 years and received the district's Teacher of Excellence award. Since 1992, he has worked on Sketchpad and Web Sketchpad software, curriculum, and professional development. He taught Secondary Math Methods in the graduate teacher education program at the University of Pennsylvania. He is a Senior Scientist at 21PSTEM and a co-principal investigator on the NSF-funded Forging Connections project.

Soccer Challenges: Angling for a Shot on Goal

With the World Cup in our hemisphere, and the US squad having started out with a win over Ghana, my thoughts turned to the mathematics of soccer. My friend Henri Picciotto has a nice page about the shooting angle, the angle within which a shot is on goal, so I thought of … Continue Reading ››

Create Parametric Curves Graphically and Kinesthetically

In this guest post, Nate Burchell describes a sketch he uses with his students to explore parametric functions. In this process students work entirely in a graphical world, manipulating graphs directly rather than by way of equations. (Nate teaches in Seoul, Korea, where I enjoyed his family's hospitality when I attended ICME in … Continue Reading ››

Understand the Sine Function by Dancing It

In Where Mathematics Comes From, cognitive scientists George Lakoff and Rafael Nuñez assert that our understanding of abstract mathematical concepts relies upon our sensory-motor experiences:

“For the most part, human beings conceptualize abstract concepts in concrete terms, using ideas and modes of reasoning grounded in the sensory-motor system. The mechanism by which the … Continue Reading ››

π Day 2014

π Day has always been a special day for me, from my earliest days. In fact, I've never figured out whether I was so eager to celebrate my first π Day that I jumped the gun and sent my mom into labor early, or whether I just wanted be sure to experience all 24 hours … Continue Reading ››

Discovering the Angle Sum and Difference Identities

In my Advanced Methods class at Penn’s Graduate School of Education, my students are working in groups to create shared lesson plans using an inquiry approach. For a number of reasons it can be challenging for these pre-service teachers to identify appropriate topics for student inquiry, but sometimes the brainstorming they do turns into something … Continue Reading ››

Aligning Objects in Sketchpad

I recently got a question from a question from a user about how to line up text objects. The question was both about lining up objects on a page, and about lining them up from one page to the next, so that when you switch pages things are in the same place on every page. As … Continue Reading ››

The Wavy Wavy Bridge

At the 2013 Baltimore Regional NCTM Meeting, I gave a presentation on Picturing Functions and Functions of Pictures. In the description of my presentation I’d promised to show how to use Sketchpad to create special effects, so when it came time to prepare, I figured I needed to deliver on my promise. So I wrote a … Continue Reading ››

Picturing Functions and Functions of Pictures

I’m excited to be making my first presentation of the 2013-14 school year next week in Baltimore. Daniel Scher and I are presenting Picturing Functions and Functions of Pictures. We'll be discussing the connections between pictures and functions. These connections are even richer than I realized when I first began to work with pictures in Sketchpad. In the … Continue Reading ››