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

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.

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.