Abstract. Education research has identified strategic flexibility as an important aspect of math proficiency and learning. This aspect of student learning has been largely ignored by Intelligent Tutoring Systems (ITSs). In the current study, we demonstrate how Hidden Markov Modeling can be used to identify groups of students who use similar strategies during tutoring and relate these findings to a measure of strategic flexibility. We use these results to explore how strategy use is expressed in an ITS and consider how tutoring systems could integrate a measure of strategy use to improve learning.