Metz, MartinaSabbaghan, SoroushPreciado Babb, PaulinoDavis, Brent2015-08-102015-08-102015-06Metz, M., Sabbaghan, S., Preciado, P. & Davis, B. "One Step Back, Three Forward: Success Through Mediated Challenge" (2015). In Preciado Babb, P., Takeuchi, M., & Lock, J. (Eds.). Proceedings of the IDEAS: Designing Responsive Pedagogy Conference, pp. 178-186. Calgary, Canada: Werklund School of Education, University of Calgary.978-0-88953-384-4http://hdl.handle.net/1880/50872How can you keep all students engaged in deepening their mathematical understanding without overwhelming the weakest students or boring the strongest? Teachers in the Math Minds project design lessons around structured sequences that seek to engage all students with questions on which they can succeed, and to then proceed through increasingly sophisticated variations. Teachers attend closely to student responses so that they can adjust difficulty in a manner that allows success and challenge for all. In this paper, we describe key principles that have emerged from the Math Minds initiative. We draw particular attention to variation theory (Marton, 2015) and consider how it plays out in interaction with the other principles.enMathematics educationMastery learningVariation theoryunknown10.11575/PRISM/5312