题目内容
计算
(1)-3-4+19-11+2
(2)3×(-4)+(-28)÷7
(3)(
-
-
)×36
(4)1
×(-
)×(-2.5)÷(-
)
(5)|-1
|÷(
-
)-
×(-3)2
(6)1-
×[3×(-
)2-(-1)4]+
÷(-
)3.
(1)-3-4+19-11+2
(2)3×(-4)+(-28)÷7
(3)(
| 1 |
| 2 |
| 5 |
| 6 |
| 2 |
| 9 |
(4)1
| 2 |
| 3 |
| 4 |
| 9 |
| 25 |
| 3 |
(5)|-1
| 1 |
| 5 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 3 |
(6)1-
| 1 |
| 2 |
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2 |
分析:(1)根据有理数的加减混合运算顺序进行运算即可;
(2)先算乘除,再算加减即可;
(3)根据乘法分配律进行计算;
(4)把带分数与小数都化为假分数,除法转化为乘法运算,然后进行计算即可求解;
(5)去掉绝对值号,然后先算除法与乘方运算,再算减法运算即可;
(6)根据有理数的混合运算顺序,先算乘方,再算乘除,最后算加减,有括号的先算括号里面的,进行计算即可.
(2)先算乘除,再算加减即可;
(3)根据乘法分配律进行计算;
(4)把带分数与小数都化为假分数,除法转化为乘法运算,然后进行计算即可求解;
(5)去掉绝对值号,然后先算除法与乘方运算,再算减法运算即可;
(6)根据有理数的混合运算顺序,先算乘方,再算乘除,最后算加减,有括号的先算括号里面的,进行计算即可.
解答:解:(1)-3-4+19-11+2,
=(-3-4-11)+(19+2),
=-(3+4+11)+(19+2),
=-18+21,
=3;
(2)3×(-4)+(-28)÷7,
=-12+(-4),
=-16;
(3)(
-
-
)×36,
=
×36-
×36-
×36,
=18-30-8,
=18-38,
=-20;
(4)1
×(-
)×(-2.5)÷(-
),
=
×(-
)×(-
)×(-
),
=-
×
×
×
,
=-
;
(5)|-1
|÷(
-
)-
×(-3)2,
=|-
|÷
-
×9,
=
×
-3,
=9-3,
=6;
(6)1-
×[3×(-
)2-(-1)4]+
÷(-
)3,
=1-
×(3×
-1)+
÷(-
),
=1-
×(
-1)+
×(-8),
=1-
×
-2,
=1-
-2,
=-
.
=(-3-4-11)+(19+2),
=-(3+4+11)+(19+2),
=-18+21,
=3;
(2)3×(-4)+(-28)÷7,
=-12+(-4),
=-16;
(3)(
| 1 |
| 2 |
| 5 |
| 6 |
| 2 |
| 9 |
=
| 1 |
| 2 |
| 5 |
| 6 |
| 2 |
| 9 |
=18-30-8,
=18-38,
=-20;
(4)1
| 2 |
| 3 |
| 4 |
| 9 |
| 25 |
| 3 |
=
| 5 |
| 3 |
| 4 |
| 9 |
| 5 |
| 2 |
| 3 |
| 25 |
=-
| 5 |
| 3 |
| 4 |
| 9 |
| 5 |
| 2 |
| 3 |
| 25 |
=-
| 2 |
| 9 |
(5)|-1
| 1 |
| 5 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 3 |
=|-
| 6 |
| 5 |
| 2 |
| 15 |
| 1 |
| 3 |
=
| 6 |
| 5 |
| 15 |
| 2 |
=9-3,
=6;
(6)1-
| 1 |
| 2 |
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2 |
=1-
| 1 |
| 2 |
| 4 |
| 9 |
| 1 |
| 4 |
| 1 |
| 8 |
=1-
| 1 |
| 2 |
| 4 |
| 3 |
| 1 |
| 4 |
=1-
| 1 |
| 2 |
| 1 |
| 3 |
=1-
| 1 |
| 6 |
=-
| 7 |
| 6 |
点评:本题考查的是有理数的运算能力.注意: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.
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