Learning algebra is critical for students in the USA today, yet many students in the USA struggle in algebra classes. Researchers claim that one reason for these difficulties is that algebra classes often focus on symbol manipulation and procedures above, and many times at the expense of, a more conceptual understanding of the content. Teaching algebra in a more conceptual way, however, can be quite challenging for teachers. This study explores the development of teacher noticing as a way to help teachers learn to broaden their views of algebra, pay attention to a wide range of student algebraic thinking, and reason about students' ideas in substantive ways. This study takes place in the context of a video club in which seven preservice teachers watched and discussed video excerpts from algebra classes over an 8-week period. A framework for noticing student algebraic thinking was created and used to structure the discussions in the video club. In addition, a new, online video-tagging tool was used to document the development of the teachers' ability to notice student algebraic thinking. Results suggest that participating in the video club helped teachers more consistently attend to substantive student algebraic thinking and to reason about this thinking they noticed in deeper ways.