In this article, the authors share two examples of student engagement in visible, mathematical thinking through a Chalk Talk within the four walls of the classroom, as well as the connected spaces of online learning. Five steps for facilitating the Chalk Talk are outlined, with descriptions of teacher moves for each step. The silent thinking routine described in this article ensures that each and every student voice is heard and that all students engage in thinking in a collaborative way. Whether students are learning in a physical classroom or online, Chalk Talk makes thinking visible and builds mathematical understanding for each and every student in an interactive, collaborative learning environment.