Máquinas simples y complejas
Grade 3-4, Physical,
Machines Unit
This book, translated into Spanish, explains that machines help people do work. Machines can help make work easier, faster, and safer. The amount of work required depends on the amount of force needed and the distance to be traveled. Seven types of simple machines are described: inclined plane, wedge, screw, lever, wheel and axle, gear, and pulley. Each machine can be found in many common devices. Complex machines combine several simple machines into one new machine in order to perform specific jobs.

