Learn how many times the human heart beats in an average lifetime (about 2.5 billion times) and how many breaths we take a day (about 20,000)! Then share these fascinating facts with family and friends to challenge their brains! With more than 100 activities from Sudoku games to fingerprint mazes and chromosome matching--plus over 50 stickers--curious kids will be busy exploring the incredible human body from head to toe in this amazing STEM activity book.