Flipped instruction is increasing in popularity, however research that moves beyond descriptions of its implementation in mathematics classes is lacking. We sought to better understand how students taking an introductory college algebra course used the resources provided within a flipped instructional model and how students viewed such resources as useful to their learning. Data from course activity records and student usage surveys were used to characterize the frequency of student access to course resources (e.g. video lectures and comprehension assessments) and students' perceptions of the usefulness of these resources. Students naturally fell into one of four categories with respect to video usage and success in the course. Students who employed videos as intended were successful in the class. Students rated watching videos and working on homework in class as the activities that best supported their learning. Students did not perceive group work and in-class presentations as helpful. Our findings have implications for other instructors implementing flipped instruction. We argue that while flipping collegiate mathematics courses has great potential, instructors need to explicitly attend to the design of the in-class components in order to maximize student learning.