We have a new tool among the options for this Activity, a pop-up graphing calculator from the Flash & Math project, that you can access by clicking on the Flash & Math icon in the text. We will occasionally provide tools adapted from this project. If you happen to have a graphing calculator at hand, it can probably do everything in these tools (and then some), but you may find it more convenient to use ours. If you have started working with one of our computer algebra systems, you may prefer to continue using the worksheets provided. The choice is up to you.