For the past few years I've taught methods courses for both beginning and experienced teachers of mathematics. One element of these courses has been the use of videos of teachers in the classroom to prompt discussion of specific aspects of practice. The lesson captured in a set of video clips here, "Looking for Squares" by Lisa Brown, is one of the best examples I've found of a teacher's use of questioning to guide students' exploration and eventual sense-making of a mathematical concept, in this case square numbers and square root. It might be helpful to read "Questioning our Patterns of Questioning" by Herbel-Eisenmann and Brefogel, to provide a context for thinking about the use of questioning in a mathematics classroom. What specific strategies and teaching skills does Ms. Brown use to promote, sustain, and engage student thinking? How does this support their sense-making?