ABSTRACT
In high-performing urban schools, teachers ensure that students have at least a moderate understanding of a concept before they ask students to perform the task independently. Generally, students are not asked to practice what they have not learned. In more typical schools, students are often pushed to work independently on tasks that they are ill prepared to pursue. As a result, in more typical schools, students often spend hours practicing
incorrect strategies, algorithms, and processes. The misunderstandings, after they have been practiced to perfection, are difficult to correct.
