Grover's 10 Terrific Ways to Help Our Wonderful World (Pictureback(R))

Illus. in full color. A jam-packed amalgam of puzzles, experiments, optical illusions, secret codes, and more are clearly explained in this brain-boggling activity book. Every puzzle, trick, and project can be executed with safe, inexpensive materials found around the home and the lively step-by-step instructions make each activity easy to follow.