It would be a shame for Calculus students to get behind the wheel of a car and not even realize that their favorite subject is being displayed right there on the dashboard. The speedometer represents your velocity function while the odometer represents your "distance traveled" function. In this construction, press "start," drag the speedometer needle, and examine how distance traveled may be viewed as the "area under the velocity curve." At least on my computer, this construction runs poorly inside a web browser. Downloading the Geogebra file is recommended.