Inspired by real-life makers Ada Lovelace and Marie Curie, this beloved #1 bestseller champions STEM, girl power and women scientists in a rollicking celebration of curiosity, the power perseverance, and the importance of asking 'Why?'.  Ada Twist's head is full of questions. Like her classmates Iggy and Rosie (stars of their own New York Times bestselling picture books), Engineer-Ada has always been endlessly curious. Even when her fact-finding missions and elaborate scientific experiments don't go as planned, Ada learns the value of thinking her way through problems and continuing to stay curious.