问题 解答题
下面各题,怎样算简便就怎样算.
①1080+270÷18-864        ②7.54+
12
7
+2.46+
16
7
③(2.4-
23
20
)÷0.625+
4
5
④2.5×12.5×40×0.8⑤98.9×99+98.9           ⑥40.5÷
1
4
×[(1-
1
4
)×1.2].
答案

①1080+270÷18-864

=1080+15-864,

=231;

②7.54+

12
7
+2.46+
16
7

=(7.54+2.46)+(

12
7
+
16
7
),

=10+4,

=14;

③(2.4-

23
20
)÷0.625+
4
5

=(2.4-1.15)÷0.625+0.8,

=1.25÷0.625+0.8,

=2+0.8,

=2.8;

④2.5×12.5×40×0.8

=(2.5×40)×(12.5×0.8),

=100+10,

=110;

⑤98.9×99+98.9

=(99+1)×98.9,

=100×98.9,

=9890;

⑥40.5÷

1
4
×[(1-
1
4
)×1.2]

=40.5÷

1
4
×[
3
4
×1.2],

=40.5×4×0.9,

=145.8.

单项选择题
单项选择题 A1/A2型题