3.8×0.02的積是
位小數(shù),如果把因數(shù)0.02擴大100倍,要使積不變,另一個因數(shù)的小數(shù)點應該
縮小100倍
縮小100倍
分析:根據(jù)小數(shù)乘法的計算法則可知,積的小數(shù)位數(shù)等于兩個因數(shù)小數(shù)位數(shù)之和,3.8一位小數(shù),0.02是兩位小數(shù),所以積是三位小數(shù);再根據(jù)積的不變的性質,一個因數(shù)擴大幾倍,另一個因數(shù)縮小相同的倍數(shù),積不變.據(jù)此解答.
解答:解:3.8一位小數(shù),0.02是兩位小數(shù),所以積是三位小數(shù);
如果把因數(shù)0.02擴大100倍,要使積不變,另一個因數(shù)的小數(shù)點應該縮小100倍.
故答案為:三;縮小100倍.
點評:此題解答關鍵是明確:積的小數(shù)位數(shù)等于兩個因數(shù)小數(shù)位數(shù)之和.
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