Meet Sherlock Bones and his trusted companion, Dr. Catson--and join them on a fun math mystery adventure! This activity storybook has a cool "reveal feature" with a magnifying device. Sherlock Bones and Dr. Catson are on the case, out to catch cunning criminals! Come along and help, as they use addition, subtraction, and some fractions to break codes, make it through mazes, and follow a trail of puzzles. It's up to kids to figure out the answers, solve robberies (including of a priceless diamond), and foil Professor Moriratty's evil plans.