This study established a cartoon-based mathematics concept learning system. It examined the effect of three different teaching modules, discussion-based concept cartoons (n = 29), teacher-oriented concept cartoons (n = 26), and worksheet teaching (n = 23), on the mathematics achievement of fifth graders in Taiwan. Two groups of students used computers to learn mathematics with concept cartoons, and the other one used a worksheet. It was found that the group using discussion-based concept cartoons performed significantly better than the other two groups, and students taught with discussion-based concept cartoons with computers achieved better performance than those taught with the conventional method.