长度单位的学习重点在于让学生建立长度表象,发展长度的空间观念。表象的建立要在学生多次的操作中体验、感悟,对实际物体的估测和测量则是利用初步建立起的长度表象解决问题,使学生在猜一猜、量一量、议一议的过程中获得知识,提升能力。 Length units of learning focus is to allow students to establish the length of appearance, the development of space concept of length. The appearance of the establishment of students in many operations to experience, perception, estimation and measurement of actual objects is the use of the initial establishment of the length of the image to solve the problem, so that students guess the amount of a discussion Gain knowledge and improve ability in the process.