Using a Simple Optical Rangefinder to Teach Similar Triangles
Paul Cuicchi, Paul Hutchison
How we taught the concept of similar triangles using an optical method of estimating large distances as a corresponding activity. The derivation of a formula to calculate one source of measurement error is included and is a nice exercise in the use of the properties of similar triangles.
Discuss with Your Colleagues: Variations on a View Tube
The entire process involved when an untried problem is presented to a group of teachers. The lesson learned form their struggles are helpful reminders that we should present open-ended problems to our high school students.
Writing About the Problem Solving Process to Improve Problem Solving Performance
Writing about the executive processes of problem solving, difficulties encountered, alternative strategies that might have been used, and the problem solving process in general helped students in the treatment group to learn to use executive processes more quickly and more effectively than students in the control group.
Study Groups: Professional Growth Through Collaboration
The use of a study group as a form of professional development for high school mathematics teachers.
On the Distribution of Primes
Some aspects of the distribution of the primes, with a more direct focus on one particular recurring pattern among the primes.
Paper Folding and Conic Sections
How the conic sections can be approximated by paper-folding activities and proves why they work.