小数的读法和写法.ppt

小数的意义和性质,1.小数的意义和读写法,第1课时小数的意义,R四年级下册,知识回顾,（1）整数的计数单位有（）相邻的两个计数单位之间的进率是（）。（2）1米=（）分米1米=（）厘米1米=（）毫米（3）表示把一个整体平均分成（）份，取了其中的（）份。（4）表示把一个整体平均分成（）份，取了其中的（）份。,个、十、百、千,10,110,3100,10,100,1000,10,1,100,3,点击播放,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,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,在生活中我们会经常遇到类似的问题，你能举一些例子吗？,妈妈买菜花了10元5角；坐公交车的时候刷了1元6角,在进行测量和计算时，往往不能正好得到整数的结果，这时也常常用小数来表示。,今天我们就来学习小数的意义。,自主探究,把1m平均分成10份。,你知道每份长多少米吗？,1米平均分成10份，每份长都是1dm，也就是米。,把1m平均分成10份。,1dm,m,0.1m,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,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分米、7分米怎么表示呢？,3,0.3,0.7,7,分母都是10。,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,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,3,0.3,0.7,7,小数的小数点右边有1位。,如果把米尺平均分成100份呢？,每份是（）厘米，（）米，用小数表示是（）米。,1,0.01,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,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,0.04,0.08,填一填。,分母都是100。,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,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,0.04,0.08,填一填。,小数的小数点右边有2位。,15份怎么表示？,用分数表示为,用小数表示为0.15,0.006,0.013,分母都是1000。,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,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,0.006,0.013,小数的小数点右边有3位。,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。,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,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,0.6,0.7,0.32,（1）小数的计数单位有十分之一、（）、（）等，分别写作（）、（）、（）。,（2）7分米是1米的（），写成小数是（）米。,（3）每相邻两个计数单位间的进率是（）。,百分之一,千分之一,0.1,0.01,0.001,0.7,10,巩固深化,1.填空。,（4）0.8的计数单位是（），它有（）个这样的计数单位；0.20的计数单位是（），它有（）个这样的计数单位。,十分之一,百分之一,20,（5）1里面有（）个十分之一，0.1里面有（）个百分之一，0.01里面有（）个千分之一。,8,10,10,10,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,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,分数：（）米（）米（）米小数：（）米（）米（）米,幼儿身高8分米,桌子高85厘米,小蚂蚁身长4毫米,2.,0.8,0.85,0.004,3.看图写出分数和小数。,（1）绿色的星星占总数的多少？,（2）红色的“心”形占总数的多少？,0.4,0.3,0.1米,0.01米,0.001米,米,米,米,十分之一,0.1,百分之一,0.01,千分之一,0.001,每相邻两个计数单位之间的进率是10。,课堂小结,课后作业,1.完成P36第1,2题；2.完成练习册本课时的