摘要：The examination of teacher knowledge in practice can shed light to understand how students learn and find out why they have difficulty in learning. This paper will focus on teachers' knowledge of pattern generalization in instruction with planning. The multiple-case study design was used for this study to compare and contrast the two middle school teachers’ lesson planning and instruction. Lesson plans, pre-observation interviews, observations, and post-observation interviews were used as data collection tools. Data were analyzed by using the Mathematical Knowledge for Teaching (MKT) model. The findings showed that the two teachers used numerical reasoning in all representations and they could not have the knowledge of figural reasoning. The teachers' inadequate explanations of functional thinking caused some misunderstandings about generalization. Through the cases of these two teachers, it was observed that teachers need to have a good conceptual mathematical understanding and also knowledge of students’ thinking in order to design effective lessons.
