The purpose of this study was to explore the use of a cognitive computer tool by undergraduate calculus students as they worked cooperatively on mathematical tasks. Specific attention was given to levels of cognitive demand in which the students were engaged as they completed in-class labs with the assistance of MathCAD. Participants were assigned to eight heterogeneous working groups consisting of four students each. One group was chosen as the focus of the case study. Data included student questionnaires, individual interviews, assignments, audio transcriptions of student discussions, and video recordings. Open and axial coding was used to analyze the data. Participants believed that the use of MathCAD allowed them to explore mathematics, spend more time on interpreting results, and focus on understanding. The cognitive computer tool reduced the reliance on low-level thinking skills and allowed for creativity in problem solving, permitting students to move toward high levels of thinking.