乘法分配律在分数小数四则混合运算中的运用.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,乘法分配律在分数四则混合运算中应用,六年制,小学数学课本第十一册,乘法分配律,在分数、小数四则混合运算中的运用,1.,复习,3.,练习,2.,例题,4.,考考你,口算,:,0.25,1,5,1,2,0.75,15,0.8,0.9,5,9,4,5,14,4,7,1,6,3,4,7,4,14,2,1,2,0.2,1,4,4,5,1,9,10,前 后,口算,:,2,1,2,0.25,1,6,3,4,1,5,1,2,14,4,7,0.75,15,0.2,1,4,0.8,0.9,5,9,4,5,4,5,1,9,10,7,4,14,前 后,计算下列各题,:,(1),0.75,1.7+0.75 2.3,(2),101,0.8 0.8,1,(3),20,4,7,6,4,7,前 后,5,4,7.5,2.5,4,5,+,1,3,4,1,4,(1,2,3,0.875,+,),24,2,9,2,6.4,9,20,3.6,+,2,3,1,5,5,6,5,1,0.2,1,6,7,+,5,4,4,5,7.5,2.5,+,4,5,7.5,2.5,+,4,5,把,除法,转化成,分数的形式,前 后,2,9,2,6.4,3.6,+,6.4,9,20,3.6,+,9,20,9,20,变,除,为,乘,变,除数,为,倒数。,前 后,1,5,5,1,0.2,1,5,3,5,6,1,6,7,+,(,),3,5,6,1,6,7,+,要注意识别,公因数,不同的表示形式,。,前 后,(1,2,3,0.875,+,),24,1,4,7,8,1,4,(1,2,3,0.875,+,),24,7,8,展开时，要注意,分母与乘数,之间的关系。,前 后,练习,你能知道每题的第一步怎么做,?,3,4,1,7,4,6,7,3,0.75,+,A,6.6,4,1,4,2,5,2,0.25,+,B,前 后,3,4,1,7,4,6,7,3,0.75,+,A,(+),3,4,前 后,6.6,4,2,5,2,0.25,+,B,1,1,4,1,4,(,),前 后,判断正误,:,5,52+5,1,5,2,1,5,(),(),0.8,4,7,0.6,4,7,(0.8+0.6),4,7,前 后,1,2,判断正误,:,3,4,24,(,),24 -,1,6,2.5,4+1.5,(2.5+1.5),1,4,1,4,(),(),1,6,1,8,1,8,前 后,填一填,前 后,2,1,4,1,+,1,2,3,1.25,1,2,1,填一填,前 后,2,1,4,1,+,1,2,3,1.25,1,2,1,0.6,0.8,3,5,8,2,补一补,前 后,0.125,2,7,1,2,3,47.6,黄牛课件,中国首家,新课标免费,资源网（,不必注册，免费下载,）,请,记住我们的网址：,