《质数合数》是一节典型的概念教学课,教学内容相对来说比较抽象,与学生的生活有一定的距离。让学生经历质数与合数概念的产生过程,就要给学生在生活中寻找一个比较丰富的载体。青岛版教材借助团体操表演的情景,给出了五个方阵的人数(分别是40人、35人、32人、25人、24人),引导学生观察各方阵人数的特 “Mathematical combination of prime numbers” is a typical concept teaching class, teaching content is relatively abstract, and the student’s life is a certain distance. Let students experience the concept of prime numbers and the synthesis process, it is necessary to give students a life in the search for a rich carrier. Qingdao textbook with the help of group gymnastics performance scenarios, given the number of five square (respectively 40, 35, 32, 25, 24), to guide students to observe the square array of special