题目内容
计算:
(1)(-
)-(+0.2)+1 (2)(-2.25)+(-5.1)+
-(-4
)+(-
)
(3)(-48)÷(+
)÷(-12)×
(4)-3
÷(-5)×(-
)÷
(5)-(-14)+(-2)2-(-3)3-23 (6)-12+(-
-
+
)×(-24)
(7)-19
×16 (8)(-15)÷(+
)-(-12)×
-(+11)÷
.
(1)(-
| 6 |
| 5 |
| 1 |
| 4 |
| 1 |
| 8 |
| 9 |
| 10 |
(3)(-48)÷(+
| 7 |
| 4 |
| 7 |
| 4 |
| 3 |
| 4 |
| 1 |
| 5 |
| 3 |
| 10 |
(5)-(-14)+(-2)2-(-3)3-23 (6)-12+(-
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
(7)-19
| 15 |
| 16 |
| 7 |
| 2 |
| 2 |
| 7 |
| 7 |
| 2 |
考点:有理数的混合运算
专题:
分析:(1)(2)先化简,再分类计算;
(3)(4)先判定符号,再按照从左到右的顺序计算;
(5)先算乘方,再算加减;
(6)(7)(8)利用乘法分配律简算.
(3)(4)先判定符号,再按照从左到右的顺序计算;
(5)先算乘方,再算加减;
(6)(7)(8)利用乘法分配律简算.
解答:解:(1)(-
)-(+0.2)+1
=-
-0.2+1
=-0.4;
(2)(-2.25)+(-5.1)+
-(-4
)+(-
)
=-2.25-5.1+
+4
-
=-3
;
(3)(-48)÷(+
)÷(-12)×
=48÷
÷12×
=4;
(4)-3
÷(-5)×(-
)÷
=-
×
×
×
=-
;
(5)-(-14)+(-2)2-(-3)3-23
=1+4+27-8
=24;
(6)-12+(-
-
+
)×(-24)
=-1-
×(-24)-
×(-24)+
×(-24)
=-1+12+16-18
=9;
(7)-19
×16
=-20×16+
×16
=-320+1
=-319;
(8)(-15)÷(+
)-(-12)×
-(+11)÷
=-15×
+12×
-11×
=(-15+12-11)×
=-14×
=-4.
| 6 |
| 5 |
=-
| 6 |
| 5 |
=-0.4;
(2)(-2.25)+(-5.1)+
| 1 |
| 4 |
| 1 |
| 8 |
| 9 |
| 10 |
=-2.25-5.1+
| 1 |
| 4 |
| 1 |
| 8 |
| 9 |
| 10 |
=-3
| 7 |
| 8 |
(3)(-48)÷(+
| 7 |
| 4 |
| 7 |
| 4 |
=48÷
| 7 |
| 4 |
| 7 |
| 4 |
=4;
(4)-3
| 3 |
| 4 |
| 1 |
| 5 |
| 3 |
| 10 |
=-
| 15 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
| 10 |
| 3 |
=-
| 1 |
| 2 |
(5)-(-14)+(-2)2-(-3)3-23
=1+4+27-8
=24;
(6)-12+(-
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
=-1-
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
=-1+12+16-18
=9;
(7)-19
| 15 |
| 16 |
=-20×16+
| 1 |
| 16 |
=-320+1
=-319;
(8)(-15)÷(+
| 7 |
| 2 |
| 2 |
| 7 |
| 7 |
| 2 |
=-15×
| 2 |
| 7 |
| 2 |
| 7 |
| 2 |
| 7 |
=(-15+12-11)×
| 2 |
| 7 |
=-14×
| 2 |
| 7 |
=-4.
点评:此题考查有理数的混合运算,掌握运算顺序,正确判定符号计算即可.
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