已知45×23=1035,請(qǐng)你在橫線里填上合適的數(shù).
4.5×2.3=________×0.23=________×0.023=0.45×________=0.045×________=________×________=________×________=________.
45 450 23 230 0.0045 2300 4500 0.0023 10.35
分析:在乘法算式中,一個(gè)因數(shù)不變,另一個(gè)因數(shù)擴(kuò)大(或縮。┒嗌俦叮0除外),積就擴(kuò)大(或縮。┒嗌俦叮瑑蓚(gè)因數(shù)都縮小,那么積縮小的倍數(shù)是兩個(gè)因數(shù)縮小的倍數(shù)的積,兩個(gè)因數(shù)一個(gè)擴(kuò)大,另一個(gè)縮小,那么積擴(kuò)大或縮小的倍數(shù)是兩個(gè)因數(shù)擴(kuò)大或縮小的倍數(shù)的商;據(jù)此解答.
解答:因?yàn)椋?5×23=1035,
4.5×2.3=45×0.23=450×0.023=0.45×23=0.045×230=0.0045×2300=4500×0.0023=10.35;
故答案為:45,450,23,230,0.0045,2300,4500,0.0023,10.35.
點(diǎn)評(píng):此題主要考查乘法算式中因數(shù)的變化引起積的變化規(guī)律,應(yīng)靈活掌握和運(yùn)用.