Based off of the hit television show NUMB3RS, this lesson exposes students to equations of variation (direct, inverse, and joint) in the real world, as well as having students work with such equations in the real world context. The...

Site describes direct, inverse, and joint variation.

This five question multiple choice review quiz allows you to review the concepts of inverse variation. After selecting your final answers, click on "Check it!" to see how you did.

Find a quick, concise explanation of Combined Variation. Hyperlinks are available to explain how variables can vary directly and inversely.

Provides an explanation and examples of variation.

This comprehensive study guide highlights the main terms and formulas needed to understand graphs of rational functions. Examples are included.

Purplemath offers an extensive explanation of direct and inverse variation, containing several examples and real-world applications.

[Free Registration/Login may be required to access all resource tools.] Learn how to solve problems using scale and indirect measurement.

The mathematics tutorial explores direct and inverse variation. The lesson consists of class notes, examples, and practice problems with solutions. The teacher resource includes an activity that examines mathematical variation in art.

This site from the University of Illinois offers an excellent simulation of the quadratic formula, where you can type in different values for a, b, and c, and then view the change in the answer for x.