This series focuses on six simple machines that serve mundane to extraordinary functions. Each machine, from ramps to pulleys, is depicted and defined in its most basic form and broken down into its different parts, then shown in a variety of real-world adaptations. A wedge (cuña) is used in pencil sharpeners and door stops, and a pulley system is used in elevators and fishing rods. Vocabulary is highlighted in bold green font, and is revisited in the appended glossary, which features text definitions along with an accompanying image to illustrate the term. The term force (fuerza) appears in each of these volumes, providing a connection between the titles and the different ways force can be applied. VERDICT Ideal for curious engineers and early physics lessons about force and shapes.