Proceedings of the Annual Meeting of the Cognitive Science Society

What is the role of fraction magnitude knowledge in learningfraction addition? An experiment with 71 6th and 7 th gradestudents compared fraction addition instruction and practicewith a magnitude representation to a tightly controlled non-magnitude condition. In the magnitude condition, studentswith better fraction magnitude estimation skills benefittedmore from the conceptual instruction and this relationshipwas moderated by students’ knowledge of how magnituderelates to fraction addition and equivalence. However,students with better fraction magnitude estimation skillsbenefitted less from the practice problems with magnitude. Inthe non-magnitude condition, fraction magnitude estimationwas not predictive of learning. This study indicates thatstudents with magnitude knowledge can leverage it to learnfraction addition concepts from magnitude representations,but, for those students, magnitude representations may be adistraction from practicing the procedure.