Question

6．甲、乙兩數(shù)的和是4.545，甲數(shù)的小數(shù)點向右移動兩位后正好與乙數(shù)相等．甲、乙兩數(shù)分別是多少？

Answer 1

分析 甲數(shù)的小數(shù)點向右移動兩位就等于乙數(shù)，說明乙數(shù)是甲數(shù)的100倍，設(shè)甲數(shù)為x，乙數(shù)就是100x，再由它們的和4.545列出方程，求出甲數(shù)，進而求出乙數(shù)．

解答 解：設(shè)甲數(shù)是x，則乙數(shù)是100x，由題意得：
x+100x=4.545
  101x=4.545
     x=0.045
100x=100×0.045=4.5．
答：甲數(shù)是0.045，乙數(shù)是4.5．

點評 本題關(guān)鍵是理解小數(shù)點的移動后數(shù)字數(shù)值的變化：小數(shù)點右移一位，原數(shù)擴大10倍．小數(shù)點右移二位，原數(shù)擴大100倍．小數(shù)點右移三位，原數(shù)擴大1000倍．向左移動則縮�。�