Tag Archives: Standards for Mathematical Practice

Arranging Addends Puzzles

Arranging Addends is an interactive puzzle that I designed on a long bus ride through Alaska. The goal of the puzzle is to arrange the circles and the six numbers (1, 2, 4, 8, 16, and 32) so that three conditions are met simultaneously: The sum of the numbers in the green circle is 21, … 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 ››

Factor Patterns at Your Fingertips

Take a look at the interactive model below. Most of the numbers in the array are shaded orange, but several are blue. What is special about these blue values? They are the factors of 32, the largest number in the array. Try dragging the red point to change the dimensions of the array. You'll see that … Continue Reading ››

Discovery by Dragging

A few days ago I led a webinar on the Common Core and Sketchpad for Sketchpad beginners, and I showed four Sketchpad activities aligned with both the Content Standards and the Standards for Mathematical Practice. I mixed it up a bit by showing two … 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 ››

Learn to Multiply Like No Bunny’s Business

It started with an unassuming bunny that hopped along a number line. Jump AlongIn 2011, our team at KCP Technologies released Sketchpad Explorer for the iPad, making it possible for teachers and students to interact with desktop Sketchpad models on their iPads. We were thrilled … 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 ››

Collaborating on an Extension to a Little-Known Theorem

[Today's post is from Steven Fuchs, with whom I recently corresponded and whose enthusiasm was sufficiently infectious that I pressed him to share it here. --Scott]

One day late last spring, while teaching at St. Thomas High School in Houston, I noticed in a book a figure demonstrating Monge’s Theorem. (Don't look this up … Continue Reading ››

What Does Rowing Have to Do with Teaching Mathematics?

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Harry congratulates a rower after sweeping Yale for his last time.
Harry Parker died this summer, two weeks after coaching the Harvard rowing team to yet another sweep of all four races (varsity, JV, freshmen, and spares) against Yale and two days after accompanying his 1980 Olympic … Continue Reading ››

Introducing the Dynamic Number Project

Four years ago, my colleague Scott Steketee and I began brainstorming new Sketchpad activities for a National Science Foundation grant called Dynamic Number. Our goal was to use Sketchpad to make ideas from number, operation, early algebra, and algebra come alive through interactive models that emphasized conceptual understanding. Dynamic NumberContinue Reading ››