用豎式計(jì)算( 1、2兩題保留兩位小數(shù),3、4兩題要驗(yàn)算)
①26×0.52 ②7.24÷21.③756÷0.18 ④0.072×0.15.
解:①26×0.52=13.52;
26
×0.52
--------
52
130
--------
13.52
②7.24÷21≈0.34;
0.344
6 3
----------
94
84
----------
100
84
------------
16
③756÷0.18=4200;
4200
72
---------
36
36
---------
0
驗(yàn)算:
0.18
×4200
--------
36
72
------
756.00
④0.072×0.15=0.0108.
0.072
×0.15
--------
360
72
---------
0.01080
驗(yàn)算:
0.15
7 2
-----------
3 6 0
3 6 0
------
0
分析:按照小數(shù)乘除的計(jì)算法則進(jìn)行計(jì)算,用逆運(yùn)算進(jìn)行驗(yàn)算.
點(diǎn)評:此題考查小數(shù)的乘除計(jì)算,細(xì)心計(jì)算,弄清小數(shù)的位數(shù).