题目内容
计算:
(1)(+2)+(-11)-6;
(2)(-6)×(+8)÷(-12);
(3)-3
÷5×
;
(4)2×(-3)2-4×(-2)+10;
(5)-9÷3+(
-
)×12+32;
(6)-14-(2.5-2)×
×[4-(-1)3];
(7)(-0.25)÷(-
)×(-
);
(8)(-30)×(
-
-
).
(1)(+2)+(-11)-6;
(2)(-6)×(+8)÷(-12);
(3)-3
| 3 |
| 4 |
| 1 |
| 5 |
(4)2×(-3)2-4×(-2)+10;
(5)-9÷3+(
| 1 |
| 2 |
| 2 |
| 3 |
(6)-14-(2.5-2)×
| 1 |
| 4 |
(7)(-0.25)÷(-
| 2 |
| 3 |
| 5 |
| 8 |
(8)(-30)×(
| 1 |
| 3 |
| 5 |
| 6 |
| 3 |
| 10 |
分析:(1)先化简,再计算即可;
(2)从左往右依次计算即可;
(3)(7)将除法变为乘法,再约分计算;
(4)(5)(6)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;
(8)直接运用乘法的分配律计算.
(2)从左往右依次计算即可;
(3)(7)将除法变为乘法,再约分计算;
(4)(5)(6)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;
(8)直接运用乘法的分配律计算.
解答:解:(1)(+2)+(-11)-6
=2-11-6
=-15;
(2)(-6)×(+8)÷(-12)
=48÷12
=4;
(3)-3
÷5×
=-
×
×
=-
;
(4)2×(-3)2-4×(-2)+10
=2×9+8+10
=18+8+10
=36;
(5)-9÷3+(
-
)×12+32
=-3-
×12+9
=-3-2+9
=4;
(6)-14-(2.5-2)×
×[4-(-1)3]
=-1-
×
×[4+1]
=-1-
×
×5
=-1-
=-1
;
(7)(-0.25)÷(-
)×(-
)
=-
×
×
=-
;
(8)(-30)×(
-
-
)
=-30×
+30×
+30×
=-10+25+9
=24.
=2-11-6
=-15;
(2)(-6)×(+8)÷(-12)
=48÷12
=4;
(3)-3
| 3 |
| 4 |
| 1 |
| 5 |
=-
| 15 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
=-
| 3 |
| 20 |
(4)2×(-3)2-4×(-2)+10
=2×9+8+10
=18+8+10
=36;
(5)-9÷3+(
| 1 |
| 2 |
| 2 |
| 3 |
=-3-
| 1 |
| 6 |
=-3-2+9
=4;
(6)-14-(2.5-2)×
| 1 |
| 4 |
=-1-
| 1 |
| 2 |
| 1 |
| 4 |
=-1-
| 1 |
| 2 |
| 1 |
| 4 |
=-1-
| 5 |
| 8 |
=-1
| 5 |
| 8 |
(7)(-0.25)÷(-
| 2 |
| 3 |
| 5 |
| 8 |
=-
| 1 |
| 4 |
| 3 |
| 2 |
| 5 |
| 8 |
=-
| 15 |
| 64 |
(8)(-30)×(
| 1 |
| 3 |
| 5 |
| 6 |
| 3 |
| 10 |
=-30×
| 1 |
| 3 |
| 5 |
| 6 |
| 3 |
| 10 |
=-10+25+9
=24.
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-.
练习册系列答案
相关题目