题目内容
计算
(1)22-(-4)+(-2)+4;
(2)-1-2×(-3);
(3)(-81)÷
×
÷(-
);
(4)(
-
+
)×(-36);
(5)0-32÷[(-2)3-(-4)];
(6)(-3)2-[(-
)+(-
)]÷
;
(7)-14÷(-5)2×(-
)+|0.8-1|;
(8)-3×(-
)2-4×(1-
)-8÷(
)2.
(1)22-(-4)+(-2)+4;
(2)-1-2×(-3);
(3)(-81)÷
| 9 |
| 4 |
| 4 |
| 9 |
| 1 |
| 36 |
(4)(
| 7 |
| 9 |
| 5 |
| 6 |
| 3 |
| 4 |
(5)0-32÷[(-2)3-(-4)];
(6)(-3)2-[(-
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 12 |
(7)-14÷(-5)2×(-
| 5 |
| 3 |
(8)-3×(-
| 2 |
| 3 |
| 2 |
| 3 |
| 2 |
| 3 |
分析:(1)先化简,再相加即可;
(2)先算乘法,再算减法;
(3)将除法变为乘法,再约分即可;
(4)直接运用乘法的分配律计算;
(5)(6)(7)(8)按照有理数混合运算的顺序,先乘方后乘除最后算加减,有括号的先算括号里面的.
(2)先算乘法,再算减法;
(3)将除法变为乘法,再约分即可;
(4)直接运用乘法的分配律计算;
(5)(6)(7)(8)按照有理数混合运算的顺序,先乘方后乘除最后算加减,有括号的先算括号里面的.
解答:解:(1)22-(-4)+(-2)+4
=22+4-2+4
=30-2
=28;
(2)-1-2×(-3)
=-1+6
=5;
(3)(-81)÷
×
÷(-
)
=81×
×
×36
=576;
(4)(
-
+
)×(-36)
=-
×36+
×36-
×36
=-28+30-27
=-55+30
=-25;
(5)0-32÷[(-2)3-(-4)]
=0-9÷[(-8)-(-4)]
=0-9÷(-4)
=0+2.25
=2.25;
(6)(-3)2-[(-
)+(-
)]÷
=9-[(-
)+(-
)]×12
=9+8+3
=20;
(7)-14÷(-5)2×(-
)+|0.8-1|
=-1÷25×(-
)+
=
+
=
;
(8)-3×(-
)2-4×(1-
)-8÷(
)2
=-3×
-4×
-8÷
=-1
-1
-18
=-20
.
=22+4-2+4
=30-2
=28;
(2)-1-2×(-3)
=-1+6
=5;
(3)(-81)÷
| 9 |
| 4 |
| 4 |
| 9 |
| 1 |
| 36 |
=81×
| 4 |
| 9 |
| 4 |
| 9 |
=576;
(4)(
| 7 |
| 9 |
| 5 |
| 6 |
| 3 |
| 4 |
=-
| 7 |
| 9 |
| 5 |
| 6 |
| 3 |
| 4 |
=-28+30-27
=-55+30
=-25;
(5)0-32÷[(-2)3-(-4)]
=0-9÷[(-8)-(-4)]
=0-9÷(-4)
=0+2.25
=2.25;
(6)(-3)2-[(-
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 12 |
=9-[(-
| 2 |
| 3 |
| 1 |
| 4 |
=9+8+3
=20;
(7)-14÷(-5)2×(-
| 5 |
| 3 |
=-1÷25×(-
| 5 |
| 3 |
| 1 |
| 5 |
=
| 1 |
| 15 |
| 1 |
| 5 |
=
| 4 |
| 15 |
(8)-3×(-
| 2 |
| 3 |
| 2 |
| 3 |
| 2 |
| 3 |
=-3×
| 4 |
| 9 |
| 1 |
| 3 |
| 4 |
| 9 |
=-1
| 1 |
| 3 |
| 1 |
| 3 |
=-20
| 2 |
| 3 |
点评:本题考查的是有理数的运算能力.注意:
(1)要正确掌握运算顺序,在混合运算中要特别注意运算顺序:先三级,后二级,再一级;有括号的先算括号里面的;同级运算按从左到右的顺序;
(2)去括号法则:--得+,-+得-,++得+,+-得-.
(1)要正确掌握运算顺序,在混合运算中要特别注意运算顺序:先三级,后二级,再一级;有括号的先算括号里面的;同级运算按从左到右的顺序;
(2)去括号法则:--得+,-+得-,++得+,+-得-.
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