问题 解答题
计算下面各题,能用简便方法的要用简便方法.
76×99
36×(
5
9
+
1
4
-
1
2
2
3
+
1
2
÷
3
4
)×
1
4
4.05-1.8-1.2125×32×25
4
5
+
1
4
)÷
7
3
-
9
20
答案

(1)76×99,

=76×(100-1),

=76×100-76,

=7600-76,

=7524;

(2)36×(

5
9
+
1
4
-
1
2
),

=36×

5
9
+36×
1
4
-
36×
1
2

=20+9-18,

=11;

(3)(

2
3
+
1
2
÷
3
4
)×
1
4

=(

2
3
+
1
2
×
4
3
)×
1
4

=(

2
3
+
2
3
)×
1
4

=

4
3
×
1
4

=

1
3

(4)4.05-1.8-1.2,

=4.05-(1.8+1.2),

=4.05-3,

=1.05;

(5)125×32×25,

=(125×8)×(4×25),

=1000×100,

=100000;

(6)(

4
5
+
1
4
)÷
7
3
-
9
20

=

21
20
×
3
7
-
9
20

=

9
20
-
9
20

=0.

单项选择题
解答题