1、整十、整百、整千数加减法,万以内数的认识,、,1. 口算。,4050 9060 9010 8050 6030 10070 2070 1090 6020,2. 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:,100020003000 (元),10002000
2、,1个千,2个千,3个千,3000,10002000,123,10002000,3000,3000,试着算一算。,1个千加2个千是3个千,就是3000。,、,二、探究新知,20001000,211,20001000,1000,1000,怎样想?,2个千减1个千是1个千,就是1000。,想加法:1000( )2000,1000,20001000,1000,用减法计算:,200010001000 (元),、,二、探究新知,8050,130,13050,80,想加法:50( )130,13050,80,80,1500,900,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
3、十是8个十,就是80。,7050 800900 12050 1700900,200400 30006000 600400 90003000,1. 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,75030,13001000,540260,4200300,6300500,4600400,75030,13001000,540260,4200300,6300500,4600400,3. 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。,9006001500(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?,20006001400(人),、,