A Funhouse Mirror of Sketchpad Transformations

Did you know that The Geometer's Sketchpad is a great tool for creating funhouse mirror pictures? Sure, Sketchpad can reflect, rotate, translate, or dilate a picture, but these operations are rather tame: They transform images uniformly, producing pictures that are easily recognizable versions of the original. By contrast, Sketchpad's "custom transform" feature allows you to apply non-linear transformations … Continue Reading ››

Sketchpad Explorer Featured in Mathematics Teacher

The May issue of Mathematics Teacher (MT) has a Technology Tips article on High-Leverage iPad Apps for the Mathematics Classroom by Ayanna Perry, Emily Thrasher, and HollyLynne Lee of North Carolina State University. They explain how to transfer files to student tablets, and they make a number of recommendations … Continue Reading ››

Playing with Triangular Decompositions

Guest blogger Juan Camilo Acevedo is part of the University of Chicago's Center for Elementary Mathematics and Science Education (CEMSE) digital team, where he develops Sketchpad-based activities for Everyday Mathematics. Currently, he teaches undergraduate language classes at the University of Chicago and is writing his doctoral dissertation on Digital Humanities. Juan holds a BA in … Continue Reading ››

Understand the Sine Function by Dancing It

In Where Mathematics Comes From, cognitive scientists George Lakoff and Rafael Nuñez assert that our understanding of abstract mathematical concepts relies upon our sensory-motor experiences:

“For the most part, human beings conceptualize abstract concepts in concrete terms, using ideas and modes of reasoning grounded in the sensory-motor system. The mechanism by which the … Continue Reading ››

complex-iteration

Iteration in the Complex Plane

The cover story of the April 2014 issue of Mathematics Teacher is on "Iteration in the Complex Plane", by Robin S. O'Dell. It sounds like pretty advanced mathematics, but is surprisingly accessible with The Geometer's Sketchpad. It's all based on the surprising principle that you can multiply two complex numbers very easily if … Continue Reading ››

Simultaneous Equations in Elementary School? You Bet!

Algebra classes devote considerable time to equations in a single variable before solving multiple equations in two or more unknowns. But just because elementary-age students are not familiar with algebraic symbolism doesn't mean they can't solve simultaneous equations, too! The mathematician and educator W. W. Sawyer makes a compelling argument for the … Continue Reading ››

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