Hi everyone,

We're continuing to develop Web Sketchpad's tool capabilities, and now we've added a nice (and important) new feature: The ability to undo a tool if you've made a mistake. If you look at some of our recent blog posts on Sine of the Times (for example, http://blog.keycurriculum.com/constr...rea-triangles/), you'll see that sitting above the set of tools included with a web sketch are left and right arrows. Pressing the left arrow will undo the tool(s) that you've created and pressing the right arrow will redo the tool(s). While the undo functionality is useful for correcting mistakes, I can well imagine a student using it to back up to the beginning of a sketch and then narrating her construction steps by pressing the redo button one step at a time.