Junk Drawer Engineering: 25 Construction Challenges That Don't Cost a Thing

Gr 4–8—As the title suggests, most of the tasks described in this volume require readily available or recycled materials. The projects range in complexity from old-fashioned cup-and-string phones to "secret computer monitors" that demonstrate polarized light. They are divided into three general categories: energy (which features a variety of roller-coaster challenges), structures (buildings designed to hold a certain amount of weight), and waves (experiments with light and sound). Each project is presented with step-by-step instructions and illustrated with black-and-white photos, followed by an explanation of the science involved and ways to adapt the activity for different age groups. The strength of the text lies in the simple but clear descriptions of the science behind each challenge. Tips on how to extend or simplify each project for different ages are interesting and useful, too, although the author often proposes having middle and high school students "do the math" or calculate the forces involved, sometimes without providing much additional assistance. Readers without a background in physics may need to consult other sources. In addition, the projects are presented one after the other, with new ones often starting in the middle of a page, which makes the book harder to browse.