This math lesson from Illuminations introduces students to the various costs associated with owning a car. The material uses proportion to calculate distance and miles per gallon, as well as analyzing data using a...

This algebra lesson from Illuminations involves slope as a rate of change. Distance-time graphs for three bicyclists climbing a mountain are compared and contrasted. The material will help students understand how to...

Unsolved problems on perfect graphs, a collection for people with at least a basic knowledge of the subject. Contents include: Perfection of special classes of Berge graphs; Recognition of special classes of Berge...

This lesson from Illuminations asks students to measure the diameter and circumference of various circular objects, plot the measurements on a graph, and relate the slope of the line to π, the ratio of circumference to...

Ptplot is a set of two dimensional signal plotters components written in Java with the following properties: embeddable in applets or applications, auto-ranging, automatic or manual labeling of axes, automatic or manual...