一、教学目标:①让学生初步体验某些事件的发生是确定的,而有些则是不确定的,能初步用“一定”、“可能”、“不可能”等词语来描述生活中一些事情发生的可能性;②培养学生浓厚的数学学习兴趣,形成较好的合作学习的态度;③通过参与学习,训练学生的动手操作能力;④通过发现和提出问题的练 First, the teaching objectives: ① allow students to initially experience the occurrence of certain events is determined, while others are uncertain, and can be preliminarily used “must ”, “may ”, “impossible ” and other words To describe the possibility of some things happening in life; ② train students strong interest in mathematics learning, to form a better attitude of cooperative learning; ③ by participating in learning, training students ability to operate; ④ practice by finding and asking questions