万以内的加法和减法执教课件

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,*,万以内的加法,两位数加、减两位数,几百几十加、减几百几十,加、减法的估算,例,1,6425=,方法一,6 4 2 5=,60,4,20,5,80,9,89,8 9,方法二,6 4 2 5=,20,5,84,89,8 9,89,例,1,6425=,方法三,方法四,6 4 2 5=,60,4,85,89,8 9,6 4 2 5=,20,5,69,89,8 9,89,例,2,7249=,23,方法一,724032,32923,725022,221 23,方法二,例,2 7249=,23,方法三,方法四,729 63,6340 23,5293,20323,例,2 7249=,23,方法三,方法四,729 63,6340 23,5293,20323,返回,例,3,650,340,方法一,方法二,600300 900,5040 90,653499,650340990,90090 990,990,例,4,840,560,方法一,方法二,840500 340,340 60 280,84 5628,840560280,280,360,710,220,+280,490,800,320,270,640,990,500,220,530,50,练一练,360,710,220,+280,490,800,320,270,640,900,500,220,530,50,练一练,返回,382,246,693,381,502,198,786,335,155,452,337,241,估算下面算式的结果：,大约得600,大约得450,大约得300,大约得600,大约得100,大约得700,349,226,258,171,720,112,106,438,419,201,525,239,619,203,864,243,先估算结果，再分类：,比500大,比500小,先估算结果，再分类：,349,226,258,171,620,1,25,106,438,419,201,525,239,619,203,864,243,比500大,比500小,59,元,40,元,38,元,62,元,妈妈有100元，想买一套儿童服装，妈妈可以怎样买？,买法一,59,元,40,元,5940 99,（元）,买法二,6238 100,（元）,38,元,62,元,买法三,5938 97,（元）,59,元,38,元,