Dynamic learning environments provide a variety of opportunities for learners to explore mathematical concepts. The purpose of this study was to explore the nature of the growth of 4 prospective middle school mathematics teachers’ understanding of geometric translations in a technology mediated environment using GeoGebra as a pedagogical medium. Individual teaching experiment methods were used to examine the progress of prospective teachers’ understanding of geometric translations. The study design included three phases: (1) semistructured clinical interviews; (2) teaching episodes; and (3) a retrospective analysis of the semistructured clinical interviews and teaching episodes. The findings of the study indicated that the availability of the dynamic geometry software supported the teacher candidates’ understanding of geometric translations. Specifically, the dragging and measurement features of the program enabled teacher candidates to explore the properties of geometric translations, make conjectures, employ various strategies, and construct new understandings.
