AbstractBackground: Internationally, there is a growing concern for developing STEM education to prepare students for ascientifically and technologically advanced society. Despite educational bodies lobbying for an increased focus onSTEM, there is limited research on how engineering might be incorporated especially in the elementary schoolcurriculum. A framework of five comprehensive core engineering design processes (problem scoping, ideageneration, design and construction, design evaluation, redesign), adapted from the literature on design thinking inyoung children, served as a basis for the study. We report on a qualitative study of fourth-grade students’developments in working an aerospace problem, which took place during the first year of a 3-year longitudinalstudy. Students applied design processes together with their mathematics and science knowledge to the designand redesign of a 3-D model plane.