数学表象是以感知为基础的,没有感知,数学表象就不可能形成。那么在教学中教师如何帮助学生在充分感知体验中去建立表象呢?下面我就结合“体积和体积单位”一课中体积单位的教学,谈一谈自己的作法和认识。“体积和体积单位”是冀教版小学数学五年级下册第七单元第一课时的教学内容,在原有的知识结构中,学生学习了线段的长度、面的大小,建立了一维二 Mathematical representations are based on perception. Without perception, mathematical representations can not be formed. So how can teachers help students to create an adequate representation of the experience in teaching? Here I will talk about my practices and understanding in combination with the teaching of volume units in Volume and Volume Units. “Volume and volume unit ” is the teaching content of the first lesson of the seventh unit of Jiwu Pupils' fifth grade under the fifth grade. In the original knowledge structure, the students learned the length of the line segment and the size of the face and established a one-dimensional two