Conceição, JoanaRodrigues, Margarida2022-11-292022-11-292021Conceição, J., & Rodrigues, M. (2021). 3D decomposition as a spatial reasoning process: A window to 1st grade students’ spatial structuring. In M. Inprasitha, N. Changsri & N. Boonsena (Eds.), Proceedings of the 44thConference of the International Group for the Psychology of Mathematics Education (Vol. 1, p. 136). Khon Kaen, Thailand: PME.978-616-93830-0-0http://hdl.handle.net/10400.21/151113D decomposition is considered a spatial reasoning process (Davis et al., 2015). Spatial structuring is a form of abstraction that creates mental models of shapes’ structures (Battista & Clements, 1996). Since early grades, both play an important role in understanding shapes’ structures and in learning how to manipulate them flexibly and fluently. 3D shapes have a strong presence in early grades, yet there is still little research about the way students learn their structures. We seek to answer the following questions: How do 1st graders decompose 3D shapes? How are these decompositions related to spatial structuring?engMathSpatial reasoning processconference object