Simple Machines are simply fascinating in Michael Dahl's Amazing Science series. They explain how pulleys, wedges, ramps, wheels and axels, levers, and screws help people do work, making them an effective introduction to this key elementary concept. Imagine the front of a ship, the blade of an axe, or a chisel. Cut, Chop, and Stop explores wedges of various sizes. Each of these is a wedge compsed of one slanted side that comes to a sharp edge. Nails and pencil points are wedges that help people accomplish a task. Food, from watermelon slices to a piece of cake, may even be cut into wedges. Nonfiction text features including a table of contents, an index, and a glossary provide structure and guidance for intermediate readers. Dennise Shea's digital images complement the text. Simple machine characteristics are enhanced in these illustrations to provide details that make the ideas clear. The integration of text and images is esstential to communicate the design and function of each simple machine. Each book has a simple investigation, too.One involves a pencil, a piece of paper, and a couple of phone books to provide an activity to reinforce the concept of wedges, another has students are challenged to use a pulley to send a message across a room. With materials, including a spring scale, weight, ruler, shoebox, and a yardstick, students can investigate how a ramp works. Procedures and questions are easy to follow.Marshmallow Madness is an activity at the end of the text that demonstrates how a lever works. Gather a large marshmallow, pencil, ruler, and yardstick to set up your own simple machine, a lever.With an empty spool of thread, string, a paper cup, two pencils, tape, and 20 pennies, for instance, a model of a wheel and axle can be built. Students will follow the simple procedures and explore the working world of the wheel and axle.a student constructsa simple model with a 2-liter plastic bottle, cardboard, pencil, scissors, tape, and a bowl of cereal. This activity will thrill the adventuresome reader as a working screw accomplishes a task!
