Another interesting video from the Uncommon Schools youtube page. In it, a practice called "the cold call" is described. Basically, the teacher asks a question at a rapid-fire pace and calls on a random student. The point is to keep the entire class on its toes by having everyone be mentally prepared to answer the question, and to keep students engaged and listening carefully. The video notes that it's supposed to be positive and you want students to get the question right (as opposed to a "I caught you not listening" practice). The second video shows the same cold call technique used in an upper-grade math class, which would help develop mental math skills. These videos will lead me to a discussion later about challenging your students.