软件简介： 在活动中加深理解
                             ——执教《体积、体积单位的认识》反思
【案例】：
开始，师拿出两个透明的一次性塑料杯。做了一个实验，向两个杯子中分别倒入一样多的水，使两个水杯内水面一样高。                                                                                                                                                                       
然后，师先向一个水杯里投入一小段粉笔，你发现了什么？                                                                                   
生：我发现水面升高了。                                                                                                                                                                                                   
生：我发现粉笔放进去时会冒泡泡。                                                                                                                                                         
师：为什么水面会升高呢？                                                                                                               
生：因为粉笔有大小，把水挤上来了。                                                                                                                                                         
师：粉笔的大小，我们一般指粉笔占有空间大小，它就是有体积。                                                                     
师：再向另一只水杯内投入一块较大的粉笔。                                                                                                                             
生：我发现这时水面比放粉笔的水面要高。                                                                                                                                           
生：我发现橡皮沉不下去，比粉笔快，因为橡皮比粉笔要重。                                                                                   
生：做成的，它沉下去时，因为中间有空隙，所以还会冒泡泡。                                                       
师：大家的知识面真是广。密集在科学上叫“密度”，那水面要比另一个杯子水面高，                                          又是为什么呀？                                                                                                                                                                                     
生：橡皮的体积比粉笔大。                                                                                                                                                                                     
生：我还发现上升部分的水的体积就是放进去的物体的体积。                                                                                   
师：大家现查得很仔细，也很爱动脑筋。物体不仅占有空间大小，即体积，而且体积还有大小。                                                                                                                                                                                                                 
 
【反思】：                                                                                                                                                                                                                                                                          这课堂，我是从特级教师姚尚志“体积”教学那儿学来的。本课导入的设计从生活中找到了研究体积的切入点，使学生在轻松，愉悦的课堂气氛中，不仅能尽快地接触到教学内容，而且所占据的空间还有大小之别。                                                                                                                                                          学生的空间知识来自于丰富的现实生活关系非常密切。尤其是对小学阶段的学生而言，空间观念是从经验活动中逐步建立起来的，生活经验是他们发展空间观念的基础。学生在理解几何知识并发展其空间观念时，这些已有的活动经验起着非常重要的作用。联系生活中实际事物的过程可以使几何表象更加清楚，有利于建立相应的几何概念和发展他们的空间观念。
另外，通过实验，也让学生感受到了丰富的科学知识，把自然科学（物质密度，浮力）与数学知识紧密相连。