In this case study, the MARVLS augmented reality app is utilized to study students' understanding of the direction of the magnetic force encountered by a charged particle moving through a magnetic field (Lorentz force). This study uses the tools developed in the MARVLS app and integrates the mathematical sense making (MSM) framework to facilitate the process of students' understanding of mathematical relationships and physical concepts. We present this process and content in a series of semi structured think-aloud guided interview questions and map the MSM framework to diagrams, concepts, symbols, and equations of the Lorentz force. The interview results suggest using the tools (e.g. equation info box) developed within the MARVLS app along with the Merge© cube promotes a deeper understanding and an increased speed in answering the Lorentz force cross product (thus the right hand rule) 3D conceptual questions. The insights gained during the interview process also contribute to further curriculum development around these models and the MSM framework.