Lesson Plan
Curated OER

The Notorious Four-Color Problem

For Teachers 9th - 12th Standards
Take a walk through time, 1852 to 2005, following the mathematical history, development, and solution of the Four-Color Theorem. Learners take on the role of cartographers to study a United States map that is to be...
PPT
BW Walch

Creating Linear Inequalities in One Variable

For Teachers 9th - 10th Standards
Just when a young mathematician starts to feel comfortable turning word problems into linear equations, shake things up and throw inequalities in the mix. This excellent, instructive presentation takes the steps for solving an...