题目内容
计算题
(1)12-(-18)+(-7)-15
(2)-64÷3
×
(3)-63÷7+45÷(-9)
(4)(
+
-
)×(-12)
(5)(-
)×(+6)×(-10)×(-
)
(6)8+(-3)2×(-2)
(7)(-5)3×(-
)+32÷(-22)×(-1
)
(8)100+16÷(-2)4-
-|-100|
(1)12-(-18)+(-7)-15
(2)-64÷3
| 1 |
| 5 |
| 5 |
| 8 |
(3)-63÷7+45÷(-9)
(4)(
| 5 |
| 12 |
| 2 |
| 3 |
| 3 |
| 4 |
(5)(-
| 3 |
| 5 |
| 1 |
| 4 |
(6)8+(-3)2×(-2)
(7)(-5)3×(-
| 3 |
| 5 |
| 1 |
| 4 |
(8)100+16÷(-2)4-
| 1 |
| 5 |
分析:(1)先化简,再计算即可求解;
(2)将除法变为乘法,再约分计算即可;
(3)先算除法,整数加法;
(4)直接运用乘法的分配律计算;
(5)先算乘法,整数加法;
(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)将除法变为乘法,再约分计算即可;
(3)先算除法,整数加法;
(4)直接运用乘法的分配律计算;
(5)先算乘法,整数加法;
(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)12-(-18)+(-7)-15
=12+18-7-15
=30-22
=8;
(2)-64÷3
×
=-64×
×
=-12.5;
(3)-63÷7+45÷(-9)
=-9-5
=-14;
(4)(
+
-
)×(-12)
=-
×12-
×12+
×12
=-5-8+9
=-4;
(5)(-
)×(+6)×(-10)×(-
)
=-3.6+2.5
=-1.1;
(6)8+(-3)2×(-2)
=8+9×(-2)
=8-18
=-10;
(7)(-5)3×(-
)+32÷(-22)×(-1
)
=(-125)×(-
)+32÷(-4)×(-
)
=75+8×
=75+10
=85;
(8)100+16÷(-2)4-
-|-100|
=100+16÷16-
-100
=100+1-
-100
=
.
=12+18-7-15
=30-22
=8;
(2)-64÷3
| 1 |
| 5 |
| 5 |
| 8 |
=-64×
| 5 |
| 16 |
| 5 |
| 8 |
=-12.5;
(3)-63÷7+45÷(-9)
=-9-5
=-14;
(4)(
| 5 |
| 12 |
| 2 |
| 3 |
| 3 |
| 4 |
=-
| 5 |
| 12 |
| 2 |
| 3 |
| 3 |
| 4 |
=-5-8+9
=-4;
(5)(-
| 3 |
| 5 |
| 1 |
| 4 |
=-3.6+2.5
=-1.1;
(6)8+(-3)2×(-2)
=8+9×(-2)
=8-18
=-10;
(7)(-5)3×(-
| 3 |
| 5 |
| 1 |
| 4 |
=(-125)×(-
| 3 |
| 5 |
| 5 |
| 4 |
=75+8×
| 5 |
| 4 |
=75+10
=85;
(8)100+16÷(-2)4-
| 1 |
| 5 |
=100+16÷16-
| 1 |
| 5 |
=100+1-
| 1 |
| 5 |
=
| 4 |
| 5 |
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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