问题 解答题
计算下面各题,能用简便算法的就用简便算法.
(1)
7
10
÷9+
3
10
×
1
9
(2)
7
5
-
5
8
-
9
16
÷
3
2
(3)(
3
4
-
1
8
÷
5
12
(4)
4
5
÷[(
1
2
+
2
5
2
3
]
答案

(1)

7
10
÷9+
3
10
×
1
9

=

7
10
×
1
9
+
3
10
×
1
9

=(

7
10
+
3
10
)×
1
9

=1×

1
9

=

1
9

(2)

7
5
-
5
8
-
9
16
÷
3
2

=

7
5
-
5
8
-
3
8

=

7
5
-(
5
8
+
3
8
),

=

7
5
-1,

=

2
5

(3)(

3
4
-
1
8
÷
5
12

=

5
8
÷
5
12

=

3
2

(4)

4
5
÷[(
1
2
+
2
5
2
3
]

=

4
5
÷[
9
10
×
2
3
],

=

4
5
÷
3
5

=

4
3

单项选择题
单项选择题