分数混合运算(运算定律)课件

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,乘法分配律在分数四则混合运算中应用六年制小学数学课本第十一册,1,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,乘法分配律在分数、小数四则混合运算中的运用1.复习3.,2,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:0.2515120.75150.80.9594,3,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,口算:2120.251634151214470.75,4,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,计算下列各题:(1)0.75 1.7+0.75,5,5,4,7.5,2.5,4,5,+,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,+,547.52.545+13414(123 0.875,6,5,4,4,5,7.5,2.5,+,4,5,7.5,2.5,+,4,5,把,除法,转化成,分数的形式,前 后,54457.52.5+457.52.5+45把除法,7,2,9,2,6.4,3.6,+,6.4,9,20,3.6,+,9,20,9,20,变,除,为,乘,变,除数,为,倒数。,前 后,2926.43.6+6.49203.6+920920,8,1,5,5,1,0.2,1,5,3,5,6,1,6,7,+,(,),3,5,6,1,6,7,+,要注意识别,公因数,不同的表示形式,。,前 后,15510.215356167+()356167,9,(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,分母与因数,之间的关系。,前 后,(123 0.875+)24147814(123 0.,10,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,练习你能知道每题的第一步怎么做?341746730.7,11,3,4,1,7,4,6,7,3,0.75,+,A,(+),3,4,前 后,341746730.75+A(+)34前,12,6.6,4,2,5,2,0.25,+,B,1,1,4,1,4,(,),前 后,6.6 42520.25+B 11414(,13,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:5 52+515215 ()(,14,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,判断正误:34 24()24 -,15,填一填,前 后,2,1,4,1,+,1,2,3,1.25,1,2,1,填一填前 后2141+1231.25121,16,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,填一填前 后2141+1231.251210,17,补一补,前 后,0.125,2,7,1,2,3,47.6,补一补前 后0.1252712347.6,18,