整十、整百、整千数加减法.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,,整十、整百、整千数,,加减法,万以内数的认识,1.,口算40,＋,50,＝,,90,－,60,＝,,90,＋,10,＝,,80,－,50,＝,60,＋,30,＝,100,－,70,＝,,20,＋,70,＝,10,＋,90,＝,60,－,20,＝,2.,填一填1,）,80,里面有（ ）个十；,150,里面有（ ）个十2,）,500,里面有（ ）个百；,1300,里面有（ ）个百3,）,4000,里面有（ ）个千；,10000,里面有（ ）个千4,）,2000,里面有（ ）个千，,2000,里面有（ ）个百一、复习导入，揭示课题,90,30,90,30,90,100,100,30,40,8,15,5,13,4,10,2,20,,二、探究新知,,,用加法计算：,1000,＋,2000,＝,3000,（元）,,1000,＋,2000,＝,1,个千,2,个千,＋,＝,3,个千,3000,1000,＋,2000,＝,1,＋,2,＝,3,1000,＋,2000,＝,3000,3000,1000,元,2000,元,试着算一算。

1,个千加,2,个千是,3,个千，,,就是,3000,二、探究新知,2000,－,1000,＝,2,－,1,＝,1,2000,－,1000,＝,1000,1000,怎样想？,2,个千减,1,个千是,1,个千，就是,1000,想加法,：,1000,＋（ ）＝,2000,1000,2000,－,1000,＝,1000,用减法计算：,2000,－,1000,＝,1000,（元）,,冰箱比电视贵多少钱？,1000,元,2000,元,900,＋,600,＝,,1500,－,600,＝,,,,二、探究新知,80,＋,50,＝,130,130,－,50,＝,80,想加法：,50,＋（ ）＝,130,130,－,50,＝,80,80,1500,900,怎样想？,试一试8,个十加,5,个十是,13,个十，就是,130,13,个十减,5,个十是,,8,个十，就是,80,70,＋,50,＝,,,800,＋,900,＝,,120,－,50,＝,,1700,－,900,＝,200,＋,400,＝,3000,＋,6000,＝,,,600,－,400,＝,9000,－,3000,＝,1.,计算三、知识运用,600,200,9000,6000,120,70,1700,800,三、知识运用,2.,捉鼠竞赛。

4000,160,80,,,三、知识运用,,,750,＋,30,＝,1300,＋,1000,＝,540,＋,260,＝,4200,＋,300,＝,6300,＋,500,＝,4600,＋,400,＝,750,－,30,＝,1300,－,1000,＝,540,－,260,＝,4200,－,300,＝,6300,－,500,＝,4600,－,400,＝,3.,算一算，并说一说你是怎样算出来的780,2300,800,4500,6800,5000,720,300,280,3900,5800,4200,（,1,）迎宾山庄和假日宾馆一共住了多少人？,三、知识运用,4.,桂林山水美，喜迎天下人,900,＋,600,＝,1500,（人）,（,3,）你还能提出哪些数学问题？你会解答吗？,（,2,）民俗度假村比假日宾馆多住了多少人？,2000,－,600,＝,1400,（人）,四、课堂作业,作业：,第,97,页练习十九，第,3,题第,98,页练习十九，第,4,题。