不計算,判斷積的小數(shù)部分是幾位小數(shù).
425×0.03________ 4.25×0.005________
3.458×0.29________ 0.048×0.213________.
2位小數(shù) 5位小數(shù) 5位小數(shù) 6位小數(shù)
分析:根據(jù)兩個因數(shù)的小數(shù)位數(shù)直接判斷即可.
解答:(1)425×0.03,425是整數(shù),0.03是2位小數(shù);
它的積的末尾的數(shù)是5,不是0,所以積的小數(shù)的位數(shù)就是:2位;
(2)4.25×0.005,4.25是2位小數(shù),0.005是3位小數(shù);
它的積的末尾的數(shù)是5,不是0,所以積的小數(shù)的位數(shù)就是:2+3=5(位).
(3)3.458×0.29,3.458是3位小數(shù),0.29是2位小數(shù);
它的積的末尾的數(shù)是2,不是0,所以積的小數(shù)的位數(shù)就是:3+2=5(位).
(4)0.048×0.213,0.048是3位小數(shù),0.213是3位小數(shù);
它的積的末尾的數(shù)是4,不是0,所以積的小數(shù)的位數(shù)就是:3+3=6(位).
故答案為:2位小數(shù),5位小數(shù),5位小數(shù),6位小數(shù).
點評:這種類型的題目不需要計算出結(jié)果,根據(jù)兩個因數(shù)小數(shù)的位數(shù)直接判斷即可,如果積的末尾沒有0,那么積的小數(shù)位數(shù)就是兩個因數(shù)小數(shù)位數(shù)的和.