One of my favorite lessons comes from a problem I first heard posed as an open–ended assessment problem by David Clarke at an NCTM conference years ago:
The Back Page: My Favorite Lesson: Which Fits Better?
Margaret R. Meyer
Car Talk Puzzler // Got Pennies?
Seán P. Madden and Louis Lim
Students analyze items from the media to answer mathematical questions related to the article. Exponents and working with large numbers are the underlying mathematical ideas this month.
An Appeeling Activity
Joshua A. Urich and Elizabeth A. Sasse
Students peel oranges to explore the surface area and volume of a sphere.
Reader Reflections – March 2012
Reader Reflections – October 2012
Readers comment on published articles or offer their own ideas.
Reader Reflections – February 2013
Regarding the reflection “On the Area of a Circle” by Cheng, Tay, and Lee (MT April 2012, vol. 105, no. 8, pp. 564-65), it is possible to prove that one can arrange infinitely many sectors of a circle into a rectangle to show that a circle's area is π2. However, the authors' derivation is invalid because they assume their conclusion by using the area of the circle within their proof.
Derivative of Area Equals Perimeter—Coincidence or Rule?
Rina Zazkis, Ilya Sinitsky, and Roza Leikin
A familiar relationship—the derivative of the area of a circle equals its circumference—is extended to other shapes and solids.
In Search of Archimedes: Measurement of a Circle
Martin V. Bonsangue
In the absence of a decimal number system and representations for square roots, Archimedes estimated the value of pi using inscribed and circumscribed polygons to a circle.
From Blueprints to Labyrinths
Diana Cheng and David Thompson
Labyrinths inspire questions about measuring path lengths and representing patterns.
Sketching Up the Digital Duck
Kathryn G. Shafer, Gina Severt, and Zachary A. Olson
Two preservice teachers describe how using Google SketchUp, Terrapin Logo, and The Geometer's Sketchpad fosters a deeper understanding of measurement concepts.