Abstract
This chapter examines how research focused on integrated science, technology, engineering, and mathematics (STEM) education conceptualizes mathematics. It responds to the concern that integrated STEM education research often treats mathematics as a tool for scientific investigation rather than viewing integrated STEM education as a site for conceptual mathematical learning. A review of literature in secondary-level STEM teaching and learning published from 2013 to 2018 in 19 international science, technology, engineering, and/or mathematics-focused journals identified 32 articles that focused on mathematically rich approaches. Analysis tracked the mathematical topics, proficiencies, and practices present in each article. Cross-cutting themes in mathematically rich integrated STEM studies include communication, task authenticity, the centrality of inquiry, and the importance of informal learning spaces. The chapter closes with priorities for further international research on mathematically-accountable STEM integration.