"Let go of "I think I know the answer...""

...that's how our 8th grade Algebra teacher started the class. Not so easy advice. We're all predisposed to believing certain outcomes. It takes an open mindedness to challenge our thinking plus two rulers, a stopwatch, a quarter and some textbooks.

The teacher asked the class to design a "racetrack", a clear plastic ruler,  and to observe how the choices the students made impacted the speed of the "car" or quarter. The height of the stack of textbooks was the rise and the distance between the edge of the textbooks and the end of the ruler was the run.

Working in pairs, the students gathered and charted data by observing what happens when you vary the rise and keep the run constant, vary both the rise and the run and lastly, to vary the run and to keep the rise constant.

It's amazing what a little wonder can do for learning in a classroom.