题目内容
(2013?龙海市模拟)下面各题怎样算简便就怎样算.
| (1)360÷15-2.5×1.4 | (2)
|
(3)0.16+4÷(
| ||||||||||||||||
(4)
|
(5)43×99+43 | (6)
|
分析:(1)先算除法和乘法,再算减法;
(2)先算乘法和除法,再算加法;
(3)先算小括号里面的减法,再算除法,最后算加法;
(4)根据加法交换律和结合律进行简算;
(5)根据乘法分配律进行简算;
(6)先算小括号里面的加法,再算中括号里面的除法,最后算括号外面的除法.
(2)先算乘法和除法,再算加法;
(3)先算小括号里面的减法,再算除法,最后算加法;
(4)根据加法交换律和结合律进行简算;
(5)根据乘法分配律进行简算;
(6)先算小括号里面的加法,再算中括号里面的除法,最后算括号外面的除法.
解答:解:
(1)360÷15-2.5×1.4,
=24-3.5,
=20.5;
(2)
×
+
÷
,
=
+
,
=
;
(3)0.16+4÷(
-
),
=0.16+4÷
,
=0.16+16,
=16.16;
(4)
-
+
-
,
=(
+
)-(
+
),
=1-1,
=0;
(5)43×99+43,
=43×(99+1),
=43×100,
=4300;
(6)
÷[(
+
)÷
],
=
÷[
÷
],
=
÷
,
=
.
(1)360÷15-2.5×1.4,
=24-3.5,
=20.5;
(2)
| 5 |
| 6 |
| 2 |
| 3 |
| 4 |
| 9 |
| 1 |
| 6 |
=
| 5 |
| 9 |
| 8 |
| 3 |
=
| 29 |
| 9 |
(3)0.16+4÷(
| 3 |
| 8 |
| 1 |
| 8 |
=0.16+4÷
| 1 |
| 4 |
=0.16+16,
=16.16;
(4)
| 3 |
| 7 |
| 2 |
| 5 |
| 4 |
| 7 |
| 3 |
| 5 |
=(
| 3 |
| 7 |
| 4 |
| 7 |
| 2 |
| 5 |
| 3 |
| 5 |
=1-1,
=0;
(5)43×99+43,
=43×(99+1),
=43×100,
=4300;
(6)
| 3 |
| 5 |
| 1 |
| 5 |
| 1 |
| 3 |
| 2 |
| 9 |
=
| 3 |
| 5 |
| 8 |
| 15 |
| 2 |
| 9 |
=
| 3 |
| 5 |
| 12 |
| 5 |
=
| 1 |
| 4 |
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
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