在教学实践中,学生的学习起点有时远远超出教师的想象,常有把学生的已知当作是未知来探究的情况。比如苏教版《科学》中《使沉在水里的物体浮起来》一课,不少学生已经知道食盐能使蛋浮起来,如果还设计让学生去探究食盐能使蛋浮起来,显然忽视了学生的已有知识和经验,但改为让学 In teaching practice, students sometimes start learning beyond the imagination of teachers, often the student's known as unknown to explore the situation. Such as the Soviet version of “science” in “soak in the water object” lesson, many students already know salt can make the egg float up, if also designed to allow students to explore the salt can make the egg float, obviously ignored The students have the knowledge and experience, but to make learning