分数加减混合运算分数简便运算培训课件

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,*,分数加减混合运算分数简便运算,跷跷板,3,7,+,2,5,2,5,+,3,7,=,(,2,3,+,1,4,),+,3,4,2,3,+,(,1,4,+,3,4,),=,2、计算下面各题。,5,8,+,2,7,3,8,4,7,+,3,7,5,6,2、用两种方法计算下面各题。,整数加法的运算律，对分数,加法适用吗？,5,8,+,2,7,3,8,4,7,+,3,7,5,6,做一做，比一比。,1,12,(,),5,8,3,8,1,4,1,4,2,3,1,4,(,),2,3,1,4,1,12,5,8,3,8,整数加法的运算律和减法的运算性质可以推广到分数，运用这些规律可以使一些分数加减法计算简便。,a+b+c=a+(b+c),a b-c=a-(b+c),2、用简便方法计算下列各题。,5,6,8,15,1,6,1,7,16,9,16,7,15,3,7,4,7,8,15,7,5,+,9,7,9,2,7,5,+,-,7,5,+,9,7,9,2,7,1,-,1,9,17,8,17,1,4,(),7,8,3,8,（）,5,9,4,9,5,8,+,（）,5,9,4,9,5,8,3、用简便方法计算下列各题。,1,9,17,8,17,5、解方程,x,=,15,14,4,5,3,8,x,=,5,6,