Description In Wacky Contraptions: Gadgets That Whiz, Whoosh, Whirl, and Twist with Hands-On Engineering Activities, young engineers ages 9 to 12 brainstorm, design, and build devices using the engineering design process. Kids learn about simple machines, mechanical advantage, forces, energy, motion, electricity, and other physical science concepts while creating fun and fascinating prototypes that do different kinds of work. Plus, this book encourages kids to adopt a growth mindset and understand that when their projects don?t work, that?s a sign that it?s time to revise and try again!