This science activity book for children 5 to 9 explores the musculoskeletal system-bones, muscles, and joints and other connective tissues-and the amazing cells they are made of, where all growth really takes place. Sixty hands-on games, experiments, and activities show what the cells of an orange look like, how our spines are constructed, how our knees and elbows work, what calcium does for our bones, how tendons and ligaments fasten bones and muscles together, and much more. A “growth portfolio” allows young scientists to track their growth, and silly songs and lively illustrations help them remember new words and concepts. All the activities have been tested in homes and classrooms to be sure they are safe, effective, and fun.