Then you may be interested on Robbie the Robot or Turtleshell
Try a triangle toy,Triangle Madness or, in Playing BLT you will find an interactive function plotter example.
Who Wants to Be a Tcl Hacker: Quiz Game and customize the questions and answers to any subject and have some fun with your students.
Like Dot to Dots or a balance toy. There are much more you can take advantage of right here, with The Cool Language.