题目内容
计算:
(1)26+(-14)+(-16)+8
(2)(
-
+
-
)×(-36)
(3)-14-(1-0.5)×
×[2-(-3)2]
(4)18-32÷(-2)3-42×(-3)
(1)26+(-14)+(-16)+8
(2)(
| 1 |
| 2 |
| 5 |
| 9 |
| 5 |
| 6 |
| 7 |
| 12 |
(3)-14-(1-0.5)×
| 1 |
| 3 |
(4)18-32÷(-2)3-42×(-3)
分析:(1)先化简,再计算即可求解;
(2)直接运用乘法的分配律计算;
(3)(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.
(2)直接运用乘法的分配律计算;
(3)(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.
解答:解:(1)26+(-14)+(-16)+8
=26-14-16+8
=34-30
=4;
(2)(
-
+
-
)×(-36)
=-
×36+
×36-
×36+
×36
=-18+20-30+21
=-7;
(3)-14-(1-0.5)×
×[2-(-3)2]
=-1-
×
×[2-9]
=-1-
×
×(-7)
=-1+
=
;
(4)18-32÷(-2)3-42×(-3)
=18-32÷(-8)-16×(-3)
=18+4+48
=70.
=26-14-16+8
=34-30
=4;
(2)(
| 1 |
| 2 |
| 5 |
| 9 |
| 5 |
| 6 |
| 7 |
| 12 |
=-
| 1 |
| 2 |
| 5 |
| 9 |
| 5 |
| 6 |
| 7 |
| 12 |
=-18+20-30+21
=-7;
(3)-14-(1-0.5)×
| 1 |
| 3 |
=-1-
| 1 |
| 2 |
| 1 |
| 3 |
=-1-
| 1 |
| 2 |
| 1 |
| 3 |
=-1+
| 7 |
| 6 |
=
| 1 |
| 6 |
(4)18-32÷(-2)3-42×(-3)
=18-32÷(-8)-16×(-3)
=18+4+48
=70.
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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