题目内容
计算:
(1)(-30)-(-28)+(-70)-88
(2)-[3.5-(-1.13)-(-0.33)]+2.5
(3)(-11
)×(-1
)×(-0.3)×3
×(-
)
(4)1-
×[2-(-3)]2
(5)(1-1
-
+
)×(-24)
(6)-23÷
×(-
)2+(-0.8)-5×(-
).
(1)(-30)-(-28)+(-70)-88
(2)-[3.5-(-1.13)-(-0.33)]+2.5
(3)(-11
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 3 |
| 3 |
| 5 |
(4)1-
| 1 |
| 25 |
(5)(1-1
| 1 |
| 2 |
| 3 |
| 8 |
| 7 |
| 12 |
(6)-23÷
| 4 |
| 9 |
| 2 |
| 3 |
| 1 |
| 22 |
分析:(1)先去括号,然后利用加法的交换律进行取整运算;
(2)先去小括号得到原式=-[3.5+1.13+0.33]+2.5,再计算中括号的加法运算,然后进行减法运算;
(3)先确定符号,再把各分数化为假分数,然后约分即可;
(4)先进行乘方运算得到原式=1-
×(2+3)2=1-
×25,再进行乘法运算,然后进行减法运算;
(5)利用乘法的分配律得到原式=1×(-24)-
×(-24)-
×(-24)+
×(-24),再进行乘法运算,然后进行加减法运算;
(6)先进行乘方运算得到原式=-8×
×
-
-5×(-
),再进行乘法运算,然后进行加减法运算.
(2)先去小括号得到原式=-[3.5+1.13+0.33]+2.5,再计算中括号的加法运算,然后进行减法运算;
(3)先确定符号,再把各分数化为假分数,然后约分即可;
(4)先进行乘方运算得到原式=1-
| 1 |
| 25 |
| 1 |
| 25 |
(5)利用乘法的分配律得到原式=1×(-24)-
| 3 |
| 2 |
| 3 |
| 8 |
| 7 |
| 12 |
(6)先进行乘方运算得到原式=-8×
| 9 |
| 4 |
| 4 |
| 9 |
| 4 |
| 5 |
| 1 |
| 4 |
解答:解:(1)原式=-30+28-70-88
=-100-60
=-160;
(2)原式=-[3.5+1.13+0.33]+2.5
=-4.96+2.5
=-2.46;
(3)原式=
×
×
×
×
=9;
(4)原式=1-
×(2+3)2
=1-
×25
=1-1
=0;
(5)原式=1×(-24)-
×(-24)-
×(-24)+
×(-24)
=-24+36+9-14
=7;
(6)原式=-8×
×
-
-5×(-
)
=-8-
+
=-7
.
=-100-60
=-160;
(2)原式=-[3.5+1.13+0.33]+2.5
=-4.96+2.5
=-2.46;
(3)原式=
| 45 |
| 4 |
| 4 |
| 3 |
| 3 |
| 10 |
| 10 |
| 3 |
| 3 |
| 5 |
=9;
(4)原式=1-
| 1 |
| 25 |
=1-
| 1 |
| 25 |
=1-1
=0;
(5)原式=1×(-24)-
| 3 |
| 2 |
| 3 |
| 8 |
| 7 |
| 12 |
=-24+36+9-14
=7;
(6)原式=-8×
| 9 |
| 4 |
| 4 |
| 9 |
| 4 |
| 5 |
| 1 |
| 4 |
=-8-
| 4 |
| 5 |
| 5 |
| 4 |
=-7
| 11 |
| 20 |
点评:本题考查了有理数的混合运算:先算乘方,再算乘除,然后进行加减运算;有括号先算括号.
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