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.

Scott and I had lots of help. We piloted activities in classrooms across the United States, including New York, Pennsylvania, Georgia, and California. Our fantastic team of teachers not only tested and critiqued our draft lessons, but they also offered ideas for entirely new Sketchpad models based upon their understanding of where their students could benefit from a dynamic approach.

Now, four years later, we are ready to debut our materials. Nearly all of the Dynamic Number activities are available, for free, in Web Sketchpad format here.