# (In)flexibility in strategy choice when solving missing-operand algebra problems

Jeffrey K. Bye, Rina M. Harsch, Sashank Varma

### Abstract

Students must be able to flexibly choose between multiple strategies to succeed in algebra and beyond. Using a computer-based task, we measured undergraduates’ time to solve missing-operand algebra problems (e.g., $x + 3 = 5$) and ‘decoded’ individual strategy choice by regressing on their time to verify arithmetic facts related to the direct, arithmetic pattern-matching strategy (e.g., $2 + 3 = 5$) and to the inverse algebraic transformation strategy (e.g., $5 - 3 = 2$). As validated by participant self-reports, we found individual differences in strategy preference (direct vs. inverse), particularly for larger problem sizes (e.g., $7 + 9 = 16$).

**Part of symposium organized by Jenny Y-C Chan & Jeffrey K. Bye (Co-chairs): ‘Problem-solving strategy in algebra: From lab to practice’.**

###### Lecturer, Educational Psychology

Researching how people think about math & data. Teaching CogSci & programming.