Reflective and formative assessments are commonly used in both K-12 and higher education but are less common in university mathematics courses. In fact, much of mathematics education seems to be heavily reliant on summative assessments. In this article, we introduce a formative assessment in the frame of a reflective homework system that can be modified and implemented across the mathematics curriculum. We then report on a survey that we administered in the traditional university undergraduate calculus sequence that we designed to measure student attitude and perception of this reflective assessment. We hope that this study encourages faculty at other institutions to implement such assessments in their mathematics courses.