If they really know the formulas, they would start by using the given information to compute the volumes based on the evidence presented. Beyond that, I'm not at all sure that the video is going to help people who jump to such irrational conclusions to keep from doing it next time. And the time after. Actually teaching students to compute the volumes before assuming anything, seems reasonable somehow even if teaching is out of style even on a listserve called "Math-Teach". Better would be to have them express - and then graph - - volume of resulting cylinders as a function of side length of rectangles of fixed area and find the maximum. Nice algebra and it greases the skids for eventual calculus. What a concept.
At 07:38 AM 5/27/2013, Richard Strausz wrote: >And here is another Wayne. My students know the formulas for surface >area and volume, but they often make false assumptions. I like this: > >http://blog.mrmeyer.com/?p=14118 > >Richard