题目内容
计算
(1)-3+14-10-2;
(2)-2×(-3)3-5÷
×2;
(3)-24×(
+1
-0.75);
(4)-14-
×[2-(-3)2]-|
-0.52|.
(1)-3+14-10-2;
(2)-2×(-3)3-5÷
| 1 |
| 2 |
(3)-24×(
| 1 |
| 6 |
| 1 |
| 3 |
(4)-14-
| 1 |
| 6 |
| 1 |
| 3 |
分析:(1)先同号相加,再异号相加;
(2)(4)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;
(3)运用乘法的分配律计算.
(2)(4)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;
(3)运用乘法的分配律计算.
解答:解:(1)-3+14-10-2
=-15+14
=-1;
(2)-2×(-3)3-5÷
×2
=-2×(-27)-5×2×2
=54-20
=34;
(3)-24×(
+1
-0.75)
=-24×
-24×1
+24×0.75
=-4-32+18
=-18;
(4)-14-
×[2-(-3)2]-|
-0.52|
=-1-
×[2-9]-|
-
|
=-1-
×[-7]-
=-1+
-
=
-
=
.
=-15+14
=-1;
(2)-2×(-3)3-5÷
| 1 |
| 2 |
=-2×(-27)-5×2×2
=54-20
=34;
(3)-24×(
| 1 |
| 6 |
| 1 |
| 3 |
=-24×
| 1 |
| 6 |
| 1 |
| 3 |
=-4-32+18
=-18;
(4)-14-
| 1 |
| 6 |
| 1 |
| 3 |
=-1-
| 1 |
| 6 |
| 1 |
| 3 |
| 1 |
| 4 |
=-1-
| 1 |
| 6 |
| 1 |
| 12 |
=-1+
| 7 |
| 6 |
| 1 |
| 12 |
=
| 1 |
| 6 |
| 1 |
| 12 |
=
| 1 |
| 12 |
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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