Take a look at an organized physics course. The 34-section electronic textbook covers material in AP® Physics 1 and 2. Teachers use the text to supplement lectures and have the class work through the labs. Each section contains...

Volume One of the 299-page Core Knowledge History of the United States covers events from the Precolonial Period to the 1800s.

Are spiders related to crabs? Study the order of arthropods with a reading selection about animal diversity. It provides details about each class within the order, as well as vivid pictures and explanatory charts. 

This section explores how to design and conduct surveys that accurately reflect the perspectives of a larger group of people by identifying unbiased sample groups and by writing unbiased questions.

With illustrated examples, students better understand the three methods of heat transfer: conduction, convection, and radiation.

Through illustrated examples and interactive examples, students investigate the topic of the rate of heat transfer.