问题 解答题
计算下面各题,能用简便方法计算的用简便方法计算.
41×101
7.8+
3
10
+2.2+
7
10
72×(
3
8
+
4
9
2.5×1.25×32[1-(
1
5
+
3
10
)]÷
1
4
2
3
-
7
12
)÷(
2
7
+
1
8
答案

(1)41×101,

=41×100+41×1,

=4100+41,

=4141;

(2)7.8+

3
10
+2.2+
7
10

=(7.8+2.2)+(

3
10
+
7
10
),

=10+1,

=11;

(3)72×(

3
8
+
4
9
),

=72×

3
8
+72×
4
9

=27+32,

=59;

(4)2.5×1.25×32,

=(2.5×4)×(1.25×8),

=10×10,

=100;

(5)[1-(

1
5
+
3
10
)]÷
1
4

=[1-

1
2
1
4

=

1
2
÷
1
4

=2;

(6)(

2
3
-
7
12
)÷(
2
7
+
1
8
),

=

1
12
÷
23
56

=

14
69

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