"The Earth's rocks and minerals are incredibly varied, but they have many features in common. This book explores the main types of rocks, looking at their characteristics, properties, and uses"--Provided by publisher.

"A hands-on approach introduces young scientists to pulleys. Science theory and practical, fun projects teach the physics and the technology behind this simple machine. Important science curriculum is explained through historical and contemporary examples of pulleys. Step-by-step projects range from the simple to the more challenging."--

Learn how fire trucks save lives.

"A hands-on approach introduces young scientists to wheels and axles. Science theory and practical, fun projects teach the physics and the technology behind this simple machine. Important science curriculum is explained through historical and contemporary examples of wheels and axles. Step-by-step projects range from the simple to the more challenging."--

Introduces electrical circuits, discussing what they are, how they work, and how they are used.

Describes various types of machines, how they are used, and how they work. Includes fact boxes and suggested activities and projects.

Combines historical facts with relevant activities related to writing and printing.

Discusses the need for energy worldwide, what is being done to conserve it, and suggestions for alternate sources.