问题 解答题
计算下面各题:
1
8
+(
7
8
-
5
12
);
4
1
3
-2.5+1
3
4
2
3
-
1
9
-
2
9
〔16.8-(1.6+3.8)〕÷1.9;9.8×100.1;8.4÷3.5.
答案

(1)

1
8
+(
7
8
-
5
12
),

=(

1
8
+
7
8
)-
5
12

=1-

5
12

=

7
12

(2)4

1
3
-2.5+1
3
4

=4

1
3
-2
1
2
+1
3
4

=4

4
12
-2
6
12
+1
9
12

=3

7
12

(3)

2
3
-
1
9
-
2
9

=

2
3
-(
1
9
+
2
9
),

=

2
3
-
1
3

=

1
3

(4)[16.8-(1.6+3.8)]÷1.9,

=[16.8-5.4]÷1.9,

=11.4÷1.9,

=6;

(5)9.8×100.1,

=9.8×(100+0.1),

=980+0.98,

=980.98;

(6)8.4÷3.5=2.4.

单项选择题
单项选择题