This study focuses on the challenge of promoting significant mathematical discourse among preservice teachers. The study was conducted as part of an academic course that accompanies their practical training. Twenty-three math preservice teachers' learning process was examined as a result of using an analytic model designed for discourse protocols' analysis. Findings revealed that an active and dynamic process occurred, modifying teacher practice and developing critical reflective thinking among preservice teachers. The change occurred in two "ripples of influence": (1) improving discourse to one promoting learning by demonstrating hypothetical scenarios and (2) perception of the role of teachers and class management.