问题 解答题
用简便方法计算,要求写出简算的主要过程.
3
4
-
2
3
)×12÷0.1
3
8
×[
8
9
÷(
5
6
+
3
4
)]
5.58-
3
8
+5.42-
5
8

7
16
×40-
5
16
÷
1
40
答案

(1)(

3
4
-
2
3
)×12÷0.1,

=(

3
4
×12-
2
3
×12)÷0.1,

=(9-8)÷0.1,

=1÷0.1,

=10;

(2)

3
8
×[
8
9
÷(
5
6
+
3
4
)],

=

3
8
×[
8
9
÷
19
12
],

=

3
8
×
8
9
×
12
19

=

4
19

(3)5.58-

3
8
+5.42-
5
8

=(5.58+5.42)-(

3
8
+
5
8
),

=10-1,

=9;

(4)

7
16
×40-
5
16
÷
1
40

=

7
16
×40-
5
16
×40,

=(

7
16
-
5
16
)×40,

=

1
8
×40,

=5.

单项选择题
单项选择题