问题 解答题
用简便方法计算.
(1)(-
1
4
4005×162003=______;
(2)318×(-
1
9
8=______;
(3)(0.5×3
2
3
199•(-2×
3
11
200=______;
(4)0.259×220×259×643=______.
答案

(1)(-

1
4
4005×162003

=(-

1
4
4005×(422003

=(-

1
4
4005×44006

=(-

1
4
4005×44005×4

=[(-

1
4
)×4]4005×4

=(-1)×4

=-4;

(2)318×(-

1
9
8

=318×[-(

1
3
2]8

=318×(

1
3
16

=316+2×(

1
3
16

=(3×

1
3
16×32

=9;

(3)(0.5×3

2
3
199•(-2×
3
11
200

=(0.5×

11
3
199•(-2×
3
11
200

=[0.5×

11
3
×(-2)×
3
11
]199×(-2×
3
11

=

6
11

(4)0.259×220×259×643

=0.259×643×220×259

=0.259×(433×410×259

=(0.25×4)9×(4×25)9×4

=4×1018

单项选择题 A1型题
单项选择题