题目内容
计算下列各题:(1)(+10
| 1 |
| 3 |
| 1 |
| 3 |
(2)(-81)÷
| 9 |
| 4 |
| 4 |
| 9 |
(3)-32-[-5-0.2÷
| 4 |
| 5 |
(4)24×(
| 1 |
| 6 |
| 3 |
| 4 |
| 5 |
| 8 |
| 1 |
| 3 |
| 1 |
| 72 |
分析:(1)先化简,再把分母相同的利用加法交换律结合到一起;
(2)根据有理数乘除混合运算的法则,按照从左到右的顺序依次进行运算;
(3)根据有理数混合运算的顺序,先算乘方再算乘除最后算加减,有括号的先算括号里面的;
(4)先利用乘法分配律,再进行有理数的混合运算.
(2)根据有理数乘除混合运算的法则,按照从左到右的顺序依次进行运算;
(3)根据有理数混合运算的顺序,先算乘方再算乘除最后算加减,有括号的先算括号里面的;
(4)先利用乘法分配律,再进行有理数的混合运算.
解答:解:(1)(+10
)+(-11.5)+(-10
)-(+4.5)
=10
-11.5-10
-4.5
=10
-10
-11.5-4.5
=-16;
(2)(-81)÷
×
÷(-16)
=(-81)×
×
÷(-16)
=-16÷(-16)
=1;
(3)-32-[-5-0.2÷
×(-2)2]
=-9-[-5-
×
×4]
=-9-[-5-1]
=-9+6
=-3;
(4)24×(
-
-
)+(-
)2÷(-
)
=24×
-24×
-24×
+
×(-72)
=4-18-15-8
=4-41
=-37.
| 1 |
| 3 |
| 1 |
| 3 |
=10
| 1 |
| 3 |
| 1 |
| 3 |
=10
| 1 |
| 3 |
| 1 |
| 3 |
=-16;
(2)(-81)÷
| 9 |
| 4 |
| 4 |
| 9 |
=(-81)×
| 4 |
| 9 |
| 4 |
| 9 |
=-16÷(-16)
=1;
(3)-32-[-5-0.2÷
| 4 |
| 5 |
=-9-[-5-
| 1 |
| 5 |
| 5 |
| 4 |
=-9-[-5-1]
=-9+6
=-3;
(4)24×(
| 1 |
| 6 |
| 3 |
| 4 |
| 5 |
| 8 |
| 1 |
| 3 |
| 1 |
| 72 |
=24×
| 1 |
| 6 |
| 3 |
| 4 |
| 5 |
| 8 |
| 1 |
| 9 |
=4-18-15-8
=4-41
=-37.
点评:本题信息量较大,主要考查有理数的混合运算,熟练掌握运算顺序是解题的关键,运用运算定律使运算更加简便.
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