Signed Numbers

I was pleasantly surprised when my ITRT (read: tech person) at school emailed and said she found out we had a lab license for Geometer's Sketchpad (GSP). Last summer I took an online course from KeyPress to learn how to use GSP and more specifically, how it can be used in Algebra classes. I was very excited to learn more about this software and to be given examples of how it can apply to the concepts we teach in Algebra classes. Earlier in the year, I used GSP to demonstrate adding and subtracting integers. I was using it as a demonstration tool at first, projected on my SMARTBoard. One problem I found using it that way, was that the sketch itself was too small for the students to see, and I ended up having one student sit at my computer and do the manipulating. I tried to make it work, and to let students take turns doing the manipulating, but it just didn't work the way I wanted it to. It was good, however, introducing the basic concept of what I was trying to develop: addi...