This is intended to help students think about solutions to word problems, especially related rate problems. Students are first lead to structuring the problem with a diagram. Then they are asked to identify things that vary and things that don't. Next, of course, is setting up the equation and then solving the problem. I use this example in class. Geogebra clearly shows how the variables change with respect to each other. It is a very simple display, but helps those students who have difficulty beginning word problems to get started.
www.battaly.com/calc
