Solving addition and subtraction word problems is an important, yet difficult task for both elementary students and teachers. Categorizing problem types and using schema-based diagrams in teaching are regarded as effective strategies to help students conceptualize and solve word problems. Therefore, in this study, elementary preservice teachers learned how to integrate word problem types with diagrams. Using video analysis, we examined the characteristics of these preservice teachers’ understanding of addition and subtraction word problem types and their use of schema-based diagrams to represent and solve these problems. The study revealed that while participants had abilities in using diagrams to solve word problems procedurally, their conceptual understanding of problem types and accuracy in using schema-based diagrams was limited. The results implied that future research and teacher preparation should focus on improving preservice teachers’ mathematics knowledge.

Session Type: Brief Research Report