In this study, researcher investigated self-teaching experiences of instructing a math-club in an elementary school. To motivate students' mathematical thoughts and activating the desire for inquiry, five principles served as the guide-lines on making teaching decisions as well as responding to students' outcome with frequently adapting instructional plans. The frame of the curriculum and the subjects of instruction were described. By meta-analyzing the students' performance and the progress of learning behavior, the results suggested that students' mathematical thoughts, self-confidence and motivation to study mathematics had all been largely enhanced. The impact on future instruction was also discussed. In this article, the author provided a possible approach to nurturing the students' self-inquiry ability and continuing desire to learn.