一、根据运算定律填空?/p>
8.1
×
1.87
?/p>
______
×
______
250
×
(0.69
×
40)
?/p>
(______
×
______)
×
______
9.2
×
2.8
?/p>
0.799999999999999
×
2.8
?/p>
(______
?/p>
______)
×
______
二、用简便方法计算下面各题?/p>
0.668×
0.25×
40
101×
0.42
3.34
×
999
?/p>
3.34
0.553
×
101
?/p>
0.553
2×
0.25
0.73×
98
0.05×
4.17×
0.02
2.5×
1004
2.5
×
7.43
×
400
2.7
×
5.4
?/p>
7.3
×
5.4