A class investigation into the mathematics of determining the maximum size of a box spring mattress that could be carried up a stairwell. The Geometer's Sketchpad was used for the problem exploration in order to help avoid common mistakes when deriving the mathematical model. The numerical solution was described using graphical method.
David Buhl, dbuhl@nmu.edu, teaches mathematics and computer science courses to education students at Northern Michigan University, Marquette, MI 49855. He is interested in real-world problems to motivate the learning of mathematics.