In the age of STEM education, teachers consistently struggle to understand the nature of technology and how to integrate it. This multiple-case study uses the TPACK framework to explore the beliefs and practices of three elementary science and engineering teachers from an urban school district with a recently implemented 1:1 iPad policy. All three teachers participated in a professional development opportunity in which they co-developed and implemented a STEM curriculum unit in collaboration with a graduate student coach. Data sources for the study included interviews and classroom observations. Qualitative analysis revealed that although this was a co-developed unit, three distinct variations in technology integration emerged during implementation of the STEM unit. Findings explore how teacher beliefs regarding technology and iPads (whether as a "purposeful tool for differentiation" or a potential "distraction" potentially limited by technical difficulties) influence their practices.