Francesca is learning algebra. Her teacher provides her with classroom instruction and exercises to work at home, and also solves problems with the class. When concepts are new, the teacher interacts often with Francesca and her classmates, showing them how to perform operations, giving subtle hints, asking leading questions and making suggestions. As Francesca becomes more competent in her new skills, her teacher begins to back off, allowing her to work with increasing independence. Francesca’s teacher has used the constructivist principle of: