Martha the Mathemagician lives on Calculation Island (where numbers grow on trees) with her life-long best friend Oscar the Owl and her grandfather Max, who is an old and wise mathemagician. In this first book of the series, Martha is given her magic calculator and has to discover the secret code that will unlock its powers. She and Oscar meet the Halving Ladybird, the Number Eating Crocodile, the Doubling Butterfly, and the Making Five Starfish in their search for the answer. Beautifully and amusingly illustrated, the story is designed to be read with children by parent or teacher. But it will also serve young readers well as they explore the world— especially as there are so few stories that have mathematics at their heart. Martha the Mathemagician will charm children and adults alike and make the world of numbers a comfortable and exciting place to be.