C?mo funcionan las rampas, las cu?as y los tornillos (How Ramps, Wedges, and Screws Work)
C?mo funcionan las m?quinas simples (How Simple Machines Work)
Forces and motion are key concepts in the elementary science curriculum. This Spanish edition of How Simple Machines Work uses simple text and full-color photographs to help ELL students understand the principles behind simple machines. Each volume includes three diagrams to enhance comprehension. The text uses authentic language and is designed to build reading skills as well as knowledge of basic science concepts.