问题 解答题
计算各题,能简便的要用简便方法计算.
1.25×25×3.2
4.75+0.25×
1
5
21×(1-
3
7
)÷
3
16
15.75-(2
3
5
+5
3
4
(6×
2
3
-4)÷
4
5
7
9
÷
11
5
+
2
9
×
5
11
答案

(1)1.25×25×3.2,

=(1.25×0.8)×(25×4),

=1×100,

=100;

(2)4.75+0.25×

1
5

=4.75+0.05,

=4.8;

(3)21×(1-

3
7
)÷
3
16

=21×

4
7
×
16
3

=64;

(4)15.75-(2

3
5
+5
3
4
),

=15.75-5.75-2.6,

=10-2.6,

=7.4;

(5)(6×

2
3
-4)÷
4
5

=(4-4)÷

4
5

=0÷

4
5

=0;

(6)

7
9
÷
11
5
+
2
9
×
5
11

=(

7
9
+
2
9
)×
5
11

=1×

5
11

=

5
11

单项选择题
单项选择题