小学数学人教版四年级下册教学4单元小数的意义和性质1课时小数的意义

www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com分母是100的分数可以写成两位小数，探索新知二10040.0410080.08分子是几，就是几个0.01。 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com理解三位小数的改写把1米平均分成1000份，其中的1份用分数怎样表示？用小数怎样表示？探索新知二0.001m10001m www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com理解三位小数的改写第2个和第3个红色箭头所指的刻度用分数和小数分别可以怎样表示？探索新知二()m()m()m()m0.001m10001m100060.0061000130.013 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com分母是1000的分数可以写成三位小数，分子是几，就是几个0.001。探索新知二理解三位小数的改写()m()m()m()m0.001m10001m100060.0061000130.013 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com分母是10、100、1000……的分数可以用小数表示。探索新知二理解三位小数的改写()m()m()m()m0.001m10001m100060.0061000130.013 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com认识小数的计数单位和进率…亿千万百万十万万千百十一（个）十分之一百分之一千分之一….问题：1.我们在学习整数的过程中，认识了哪些计数单位？它们之间有什么关系？回顾与联系三 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com问题：2.1个一是10个（）；1个十分之一是10个（）；1个百分之一是10个（）………亿千万百万十万万千百十一（个）十分之一百分之一千分之一…101100110001认识小数的计数单位和进率.回顾与联系三 www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com小结：小数的计数单位是十分之一、百分之一、千分之一……分别写作0.1、0.01、0.001……每相邻两个计数单位之间的进率是10。认识小数的计数单位和进率…亿千万百万十万万千百十一（个）十分之一百分之一千分之一….回顾与联系三