College students have a diverse educational background with the recent multiplicity in university admissions standards and procedures. As a result, their mathematical preparation and performance varies widely. Teaching calculus to such a diverse student group is a demanding task. Differentiated curriculum has been conducted for the university calculus course in Yonsei university for the past five years. A case study on the differentiated curriculum in Yonsei university is presented for the curriculum improvement. With its ideal purpose, the differentiated curriculum has created issues and problems in practice. As an alternative to the ideal differentiated curriculum, this study shows that a computer-based approach using a numerical software could give aids to overcoming the difficulty of inadequately prepared students in the learning process while mathematically sophisticated students could keep interested in the course. This study also presents the useful topics in calculus that can be implemented for computer-based calculus education and provides guidelines for the effective usage.