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1、青島版三年級(jí)數(shù)學(xué)下冊(cè)東莊鎮(zhèn)鐘莊完小東莊鎮(zhèn)鐘莊完小 杜繼文杜繼文用豎式計(jì)算下面用豎式計(jì)算下面2 2道題:道題:612+78=679-39=0.7米米0.6米米抽油煙機(jī)離抽油煙機(jī)離地面有多高?地面有多高?0.7+0.6=(米)小數(shù)加法的計(jì)算方法:n把加數(shù)的小數(shù)點(diǎn)對(duì)齊,也就是相同數(shù)位把加數(shù)的小數(shù)點(diǎn)對(duì)齊,也就是相同數(shù)位對(duì)齊,然后按照整數(shù)加法的計(jì)算方法進(jìn)對(duì)齊,然后按照整數(shù)加法的計(jì)算方法進(jìn)行計(jì)算,最后在得數(shù)里對(duì)齊加數(shù)中的小行計(jì)算,最后在得數(shù)里對(duì)齊加數(shù)中的小數(shù)點(diǎn)點(diǎn)上小數(shù)點(diǎn)。數(shù)點(diǎn)點(diǎn)上小數(shù)點(diǎn)。0.9+0.6=1.50.7+0.3=11.9+1.8=3.74.5+2.4=6.91+0.8=1.82.4+0.9=3
2、.30.7-0.3=(米)小數(shù)減法的計(jì)算方法:n相同數(shù)位對(duì)齊,即小數(shù)點(diǎn)對(duì)齊,再按照相同數(shù)位對(duì)齊,即小數(shù)點(diǎn)對(duì)齊,再按照整數(shù)減法的計(jì)算方法進(jìn)行計(jì)算,得數(shù)的整數(shù)減法的計(jì)算方法進(jìn)行計(jì)算,得數(shù)的小數(shù)點(diǎn)要與減數(shù)(或被減數(shù))的小數(shù)點(diǎn)小數(shù)點(diǎn)要與減數(shù)(或被減數(shù))的小數(shù)點(diǎn)對(duì)齊。對(duì)齊。小數(shù)的加、減法要小數(shù)的加、減法要注意什么?注意什么?小數(shù)點(diǎn)要對(duì)齊小數(shù)點(diǎn)要對(duì)齊,也就是把也就是把相同相同數(shù)數(shù)位對(duì)齊位對(duì)齊得數(shù)的小數(shù)點(diǎn)要與得數(shù)的小數(shù)點(diǎn)要與橫線橫線上上的小數(shù)點(diǎn)對(duì)齊,千萬(wàn)不要的小數(shù)點(diǎn)對(duì)齊,千萬(wàn)不要忘了忘了點(diǎn)上小數(shù)點(diǎn)點(diǎn)上小數(shù)點(diǎn)末尾沒(méi)有末尾沒(méi)有0,一般,一般要把小數(shù)點(diǎn)后的要把小數(shù)點(diǎn)后的0補(bǔ)齊補(bǔ)齊。0.9-0.5 4 3.4+1.
3、6 5 0 4-1.3 3.30.2.7.火眼金睛辨對(duì)錯(cuò)火眼金睛辨對(duì)錯(cuò)53.32.4755.779.864.265.6 01.7 60.8 50.9 1先找出錯(cuò)在哪里,再改正。先找出錯(cuò)在哪里,再改正。53.32.477.8 09.864.265 601.760.85 91練一練練一練16.2 833.95.53.0 09.36.9 8249.913.88.37.5 64.5 60.70.31.60.40.650.254.50.50.820.4263.4口算下面各題??谒阆旅娓黝}。1 11.21.29.49.40.40.40.40.45 5用豎式計(jì)算:0.63+1.5 5.76-0.763.63-1.52 17.5-4.5 8+3.02 6.36+1.44解決生活中的數(shù)學(xué)解決生活中的數(shù)學(xué)1、上個(gè)月小芳家的電費(fèi)是、上個(gè)月小芳家的電費(fèi)是187.76元元,水費(fèi)是水費(fèi)是54.48元元,上個(gè)月小芳家的水電上個(gè)月小芳家的水電費(fèi)一共多少元費(fèi)一共多少元?說(shuō)一說(shuō)你的收獲說(shuō)一說(shuō)你的收獲