The National Council of Teachers of Mathematics identified technology as a feature of high-quality mathematics education. One way that teachers can use technology to facilitate their pupils' mathematical understanding is through the generating and exploring multiple representations of mathematical ideas. The purposes of this study are to: (1) observe and describe how pre-service mathematics teachers, who had a variety of experiences doing and practice-teaching mathematics in a technology-rich environment, subsequently incorporated technology-generated representations into their student teaching and (2) understand and expound on their rationales for using such representations. Consistent with the purposes of this study, the data collection is both descriptive and qualitative. Data were collected through various means and mediums such as observations, interviews, and artifacts. We found that these pre-service teachers appropriately utilized the provided technology to generate representations for the purpose of helping their pupils to develop conceptual understanding and reasoning. These pre-service teachers realized that technology makes possible representations that support pupils' sense making in ways that could not be actualized under typical conditions. (Contains 10 figures.)