Question

甲乙兩數(shù)的和是38.5，把乙數(shù)的小數(shù)點(diǎn)向右移動(dòng)一位，就與甲數(shù)相同．甲數(shù)是

 

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Answer 1

分析：“把乙數(shù)的小數(shù)點(diǎn)向右移動(dòng)一位，就與甲數(shù)相同”，就說(shuō)明甲數(shù)是乙數(shù)的10倍，甲乙兩數(shù)的和38.5里面就有11個(gè)乙數(shù)，所以，乙數(shù)是38.5÷11=3.5，而甲數(shù)即是3.5×10=35．

解答：解：乙數(shù)是38.5÷（10+1）=3.5
甲數(shù)是3.5×10=35
答：甲數(shù)是35．
故答案為：35．

點(diǎn)評(píng)：此題運(yùn)用了關(guān)系式：和÷（倍數(shù)+1）=1倍數(shù)（較小數(shù)），1倍數(shù)（較小數(shù)）×倍數(shù)=幾倍數(shù)（較大數(shù)）．