Preparing students with 21st Century Skills through STEM related teaching is needed, especially at the elementary level. However, most teacher education preparation programs do not focus on STEM education. To provide an exemplary STEM unit, we transformed an inquiry-based unit on moon phases from a traditional science activity into a technology-rich, digital unit for pre-service teachers (PSTs). In this paper, we describe lessons learned related to the development and implementation of this STEM unit in an undergraduate elementary methods course. We explore the impact of this on PSTs' perceptions of inquiry-based science instruction. Findings indicate that PSTs held absolutist beliefs and had a need for instruction on inquiry-based learning prior to engaging in inquiry, that explicit examples of technology use are needed, and that our design approach presented benefits and drawbacks. Implications are discussed.