Learn how to calculate sale price when combining two "percent-off" discounts in this video from KQED. In the accompanying classroom activity, students develop and share a variety of strategies, including modeling with a 10 x 10 grid to...

Provides examples and a video lesson that illustrates how to solve percent problems.

Students show comprehension of basic arithmetic skills. The online test assesses scholars on ratios, proportions, and percents.

In this feature, adapted from Interactive NOVA: Earth, students explore the relationship between oxygen concentration and the well-being of various organisms by simulating a change in oxygen levels and observing what happens.