最新苏教版五年级数学上册(第九册)《小数加法和减法》课件-1

qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin苏教版五年级数学上册苏教版五年级数学上册小数加法和减法1qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin（1）4.75的计数单位是（）,它有 （）个这样的单位。（2）3.4里有（）个0.1，有（）个0.01。（3）4.75元=（）分 3.4元 =（）分0.0147534340340475（1）4.75的计数单位是（）,它有 2qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin用竖式计算用竖式计算 835+86=968-75=835 86968 75 921 893 921 893用竖式计算 835+86=3qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin你能提出一些用加、减法计算的问题吗?你从图片中了解到了哪些信息?你能提出一些用加、减法计算的问题吗?你从图片中了解到了哪些信4qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin小明和小丽一共用了多少元？4.753.4 小明和小丽一共用了多少元？4.753.4 5 4.75+3.4=4 7 5 分分 4.75元 +3 4 0 分分 3.4元 8.15（元）8 1 5 分8.1 5 元 4.75+3.4=4 7 56qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin 小明和小丽一共用了多少元？4.75+3.4把小数点对齐，也就是相同数位对齐正确的错误的8.15（元）答：小明和小丽一共用了8.15元。小明和小丽一共用了多少元？7qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin整数加法中把什么对齐?小数加法呢?小数点对齐。末尾对齐(个位对齐)整数加法中把什么对齐?小数加法呢?小数点对齐。末尾对齐(个位8qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin(2)小明比小丽多用多少元?4.753.4=1.35(元)4 .7 5 3 .45小数减法?小数点对齐。答:小明比小丽多用1.35元。你会用竖式计算吗?3.10(2)小明比小丽多用多少元?4.753.4=1.35(元9qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin小明和小芳一共用了多少元？4.7 52.6 57.4 04.752.657.4（元）答：小明和小芳一共用了7.4元。小明和小芳4.7 52.6 57.4 04.752.6510qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin小芳比小明少用了多少元？4.7 52.6 52.1 0 4.752.65 2.1（元）答：小芳比小明多用了2.1元。小芳比小明少用了多少元？4.7 52.6 52.1 0 411qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin小数加、减法与整数加减法在计算时有什么相同点?计算小数加减法要注意什么?1.数位对齐。2.从低位算起。1.小数点对齐。2.化简结果。小数加、减法与整数加减法在计算时计算小数加减法要注意什么?112qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin.计算下面各题。9.3 2 4 1 3.8 7.5 6+6.9 8 +9.9 -8.3 -4.5 6 16.2 8 3 3.9 5.5 3.0 0.计算下面各题。16.2 8 3 3.13qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin少年宫小华家小冬家 学校2.151.550.55单位:km第3题小冬家和小华家相距多少千米？1.55+0.55=2.1（千米）少年宫小华家小冬家学校2.151.550.55单位:km第314qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin少年宫小华家小冬家 学校2.151.550.55单位:km第3题各自从家到学校，小华要比小冬多走多少千米？1.55-0.55 1（千米）少年宫小华家小冬家学校2.151.550.55单位:km第315qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin少年宫小华家小冬家 学校2.151.550.55单位:km第3题小华从家到少年宫一共要走多少千米？1.55+0.55+2.15 你还能提出哪些数学问题？4.25（千米）少年宫小华家小冬家学校2.151.550.55单位:km第316qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin53.32.4755.779.864.265.6 01.7 60.8 50.9 1先找出错在哪里，再改正。53.32.477.8 09.864.265 601.760.85 9153.32.4755.779.864.265.6 01.17qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin练习八第练习八第1 1题：口算下面各题。题：口算下面各题。0.70.3 1.60.463.40.820.420.650.254.50.511.29.40.40.45练习八第1题：口算下面各题。0.70.3 1.60.4618qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin（同桌说一说，议一议）小数加减法与整数加减法在计算时有什么相同点和不同点？计算小数加减法要注意些什么？整数加减法小数加减法相同点不同点 都要把相同数位对齐，也就是把相同数位上的数相加减，都要从低位算起。末位对齐只要把小数点对齐（同桌说一说，议一议）小数加减法与整数加减法在计算时有什么相19qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin课后作业课后作业1、复习小数加减的计算方法。2、完成书上练习八第2题。3、预习49页例2。课后作业1、复习小数加减的计算方法。2、完成书上练习八第220qing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xinqing zhen shi wang zhuang xiao xue guo kai xin谢谢大家谢谢大家感谢各位同学的合作谢谢大家21