Functional Relationships
http://www.shodor.org/interactivate/activities/LinearFunctMachine/
http://www.mathplayground.com/functionmachine.html
http://hotmath.com/util/hm_flash_movie.html?movie=/learning_activities/interactivities/function_machine.swf&return_to=Algebra%20Activities%20-%20Math%20Activities%20-%20Hotmath&title=The%20Function%20Machine