An online homework system created for use by beginning calculus students is described. This system was designed with the specific goal of supporting student engagement outside of class by replicating the attempt-feedback-reattempt sequence of events which often occurs in a teacher's presence. Evidence is presented which indicates that this goal was realized, resulting in an improvement in overall student performance. Furthermore, student survey responses indicate that a high level of satisfaction with the system was present within the class, and in particular with regards to the online homework's usefulness in helping students understand first-semester calculus concepts. The online assignments were created with general course management software which was already being used campus-wide, and therefore no additional hardware or software resources were required. (Contains 3 tables and 5 figures.)