Abstract: Studies have shown that teachers do not have good understanding of calculus concepts. This paper reports a study of teachers’ content knowledge of calculus, on 27 in-service mathematics teachers. A questionnaire dealing with the concept images and concept definitions of various calculus concepts was administered to the group of participating teachers. The responses to the questionnaire showed that most of the participants had not built up sufficiently rich and comprehensive concept images related to the various differential calculus concepts, and they generally turned to procedures in handling calculus tasks. This study sheds light on the type of calculus content needed by school teachers.

Key words: Mathematical content knowledge; Calculus; In-service teachers; Mathematical conceptions