教学目的：通过拼七巧板进一步掌握和巩固已学平面图形面积的计算公式及其推导过程，培养学生的动手能力、观察能力及想象能力，渗透事物间普通联系的观点和全面看问题的观点。教具准备：七巧板（用吹塑纸做）。新课导入（学生对话）：甲：你手里拿着什么？乙：七巧板，它是我 Teaching Objective: To further grasp and consolidate the calculation formula and the derivation process of the learned graphic area by spell jigsaw puzzle, cultivate the students' practical ability, observation ability and imagination ability, infiltrate the common connection point of things and view the problem comprehensively. Teaching aids to prepare: Tangram (made with blow molding paper). New Course Import (Student Talk): A: What's in your hand? B: Tangram, it is me