1、单击此处编辑母版文本样式,第二级,第三级,第四级,Page,*,单击此处编辑母版标题样式,分数的简单计算,胡楼小学,万亚丽,1,2,9,4,里有(,)个,9,1,6,5,是,5,个六分之(),8,7,里有,7,个,(,),(,),2,个,9,1,是(),1,里面有(,),个,1,4,,或者()个,1,8,你 真棒!,3,说说分数的具体含义。,5,3,4,4,2,9,4,喜羊羊吃了西瓜的几分之几?,美羊羊吃了西瓜的几分之几?,5,2,8,1,+,8,=,8,3,6,2,个,8,1,3,8,1,8,8,加,1,个,是,3,个,1,就是,.,7,我能行!,2,7,3,+,=,9,1,1,5,2,9,
2、2,8,5,7,+,5,=,+,=,+,8,2,=,7,5,5,3,9,3,8,7,你能总结同分母分数加法的特征吗?,8,9,10,我同样能行!,2,7,3,=,9,1,1,5,2,9,2,8,5,7,5,=,=,8,2,=,7,1,5,1,9,1,8,3,你能总结同分母分数减法的特征吗?,11,同分母分数相加减,分母不变,分子相加减。,计算方法:分母不变,只是分子相加减。,12,看谁算得又对又快。,2,7,3,7,=,5,7,4,9,2,9,=,6,9,1,5,3,5,=,4,5,2,6,3,6,=,5,6,1,8,3,8,=,4,8,1,7,6,7,=,7,7,=,1,13,14,15,试一试吧!,2,3,1,3,1,9,7,1,5,=,=,=,1,4,3,9,4,7,16,下课啦!,17,