Mathematical skills have been recognised as a core competence for engineering and science students. However, learning mathematics has been recognised as a difficult and challenging task for most students, in particular, calculus for first-year students in university. Consequently, the development of effective learning strategies and environments for mathematics courses has become an important issue. To this end, a mathematics learning system based on an instant diagnostic and guiding strategy is proposed to enhance students' calculus learning outcomes. Moreover, an experiment has been conducted in a university calculus course to evaluate the effectiveness of the proposed method. The experimental results show that the proposed approach not only improved the students' learning performance, but also improved their confidence in learning calculus. Further findings are also discussed.