考點:小數(shù)乘法
專題:運(yùn)算順序及法則
分析:0.084×0.24中,4×4=16,積的末尾沒有0,所以積的小數(shù)位數(shù)是兩個因數(shù)小數(shù)位數(shù)的和;
1.35×0.2中5×2=10,積的末尾產(chǎn)生0,先計算出1.35×0.2的積,再進(jìn)一步求解.
解答:
解:①因為0.084是三位小數(shù),0.24是兩位小數(shù),
所以0.084×0.24的積的小數(shù)位數(shù)是:3+2=5(位);
②1.35×2=2.7
1.35×0.2的積有一位小數(shù).
故答案為:五,一.
點評:在小數(shù)乘小數(shù)的計算中,積的小數(shù)位數(shù)是兩個因數(shù)小數(shù)位數(shù)的和,注意積的末尾有0時,需要進(jìn)行計算,才能準(zhǔn)確得出積的小數(shù)位數(shù).