第7课时-容积和容积单位(2).ppt

1、R五年级下册,第7课时 容积和容积单位（2）,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,温故知新,体积单位与容积单位,常用的体积单位有立方米（m3）、 立方分米（dm3）、立方厘米（cm3）, 每相邻两个体积单位间的进率是1000 1m3=1000dm3 1dm3=1000cm3,

2、计量容积，一般就用体积单位。,计量液体的体积时，常用容积单位升（L） 和毫升（ml）。,1L=1dm3 1ml=1cm3 1L=1000ml,我们已经学会了求长、正方体的体积，现实生活中还有很多像橡皮泥、梨、石块等形状不规则的物体，怎样求得它们的体积呢？,新课引入,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路

3、,状元成才路,状元成才路,设法求出下面两种物体的体积。,橡皮泥,探究新知,阅读与理解,橡皮泥,要解决求体积的问题，这些物体的特点是形状不规则。,橡皮泥,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,分析与解答,可以把橡皮泥捏压成规则的长方体或正方体形状，再求长方体或正方体的体积。,不能

4、改变形状的梨怎么办呢？,水的体积是 _mL。,水和梨的体积是_mL。,200,450,水面上升的那部分水的体积就是梨的体积。,梨的体积： 450-200=250（cm3）,用排水法求不规则物体的体积需要记录哪些数据？,答：_ _,需要记录水的体积以及放入不 规则物体后总的体积。,回顾与反思,可以利用上面的方法测量乒乓球、冰块的体积吗？为什么？,不能用排水法测量乒乓球和冰块的体积。因为兵乓球没有沉入水中而冰块又与水融合在一起了。,答：,想一想,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路

5、,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,1.平均每个西红柿的体积是多少立方厘米？,达标检测,200mL200cm3 350mL350cm3 350200150(cm3) 150275（cm3） 答：平均每个西红柿的体积是75cm3。,2.一个长100cm，宽80cm的长方体水槽中，放入一个长方体铁块。铁块完全浸入水中时，水面上升了4cm。如果铁块的长是40cm，宽是20cm，那么它的高是多少厘米？,100804（4020） 320

6、00800 40（cm） 答：它的高是40cm。,巩固提高,1.珊瑚石的体积是多少？,8cm,8cm,6cm,8cm,8cm,7cm,761（cm） 88164（cm3） 答：珊瑚石的体积是64cm3。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,2.一个长方体玻璃容器，从里面量长、

7、宽均为2dm， 向容器中倒入5.5L的水，再把一个苹果放入水中。 这时量的容器内的水深是15cm。 这个苹果的体积是多少？,15cm=1.5dm,苹果和水的体积= 221.5=6（dm3）=6（L）,苹果的体积=6-5.5=0.5（L）,答：苹果的体积是0.5L。,课堂小结,求不规则物体的体积,两次的体积差就是不规则物体的体积。,把不规则的物体转化为规则的。,课后作业,1. 课本练习九，第8题、第9题； 2. 完成练习册本课时的习题。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,声 明 本文件仅用于个人学习、研究或欣赏，以及其他非商业性或非盈利性用途，但同时应