The MSUrbanSTEM fellowship program aims to support science, technology, engineering, and mathematics (STEM) educators teaching in an urban context. In this chapter, we used a multiple case studies methodology to examine the qualitatively different ways three urban mathematics educators implemented a yearlong project in their mathematics classrooms to support student learning. Through the use of innovative professional development offered by the MSUrbanSTEM instructors, these Chicago Public School (CPS) educators focused their projects around the idea of wonder, disciplinary focus, and strategic technology integration to transform their instruction and practice in their schools.