The mission of OCTM eJournal is to provide a venue for mathematics teachers and their students in grades K-12 to share teaching ideas and content knowledge, with emphasis placed on activities that foster student inquiry through the use of technology, and to provide a venue for critical dialog that empowers teachers to challenge assumptions of best practices in the 21st century.

Activities and Teaching Modules

Two Problems

by Suzanne Harper and Todd Edwards

Students consider various triangle centers as they explore two rich, real-world mathematics tasks, The Pumping Station and Choosing a House. Both problems are explored using web-accessible java applets (Pumping Station Applet, Choosing a House Applet). The Choosing a House task asks students to find the location of a house equidistant from three neighborhood schools. Students build conjectures using a mix of traditional tools and dynamic geometry software, connecting conjectures to their community using Google Maps.

Ceva's Theorem

by Alex Garvin and Todd Edwards

Ceva's Theorem, although not commonly taught in high school classrooms, is closely connected to a variety of topics familiar to most any secondary geometry course. For instance, the following are direct results of Ceva's Theorem: (a) The medians of a triangle intersect in a single point, the centroid; (b) The altitudes of a triangle intersect in a single point, the orthocenter; (c) The angle bisectors of a triangle intersect in a single point, the incenter. Ceva's Theorem is explored with students using an interactive java applet (Ceva's Theorem Applet)

Applets

Slope and Angle Practice

by Steve Phelps

This applet allows students to practice using the TAN function to find the angle formed by a line and the postive x-axis in the coordinate plane.

This applets supports the following 10th grade Benchmark for Patterns, Functions, and Algebra: Describe the relationship between slope of a line through the origin and the tangent function of the angle created by the line and the positive x-axis.