Martha the Mathemagician and the Medieval Castle

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 second book of the series, Martha uses her magic calculator for the first time.

She and Oscar are transported to a dramatic argument between Knights about who will save the Princess from the dragon.

Again she meets the Halving Ladybird to solve the problem she faces.

Oh, and empowers the Princess while she's at it... 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.