题目内容
计算:
(1)0.47-4
-(-1.53)-1
;
(2)(
-
+
)×(-30);
(3)-15-[-1-(4-20)];
(4)(
-
)÷1
÷
×
;
(5)16÷(-2)-(-
)×(-4)2+(-1)2009;
(6)
+
+
+…+
;
(7)100+16÷(-2)4-
×(-5)2-|-100|;
(8)-14-[2-(1-
×0.5)]×[32-(-2)2].
(1)0.47-4
| 5 |
| 6 |
| 1 |
| 6 |
(2)(
| 9 |
| 10 |
| 1 |
| 15 |
| 1 |
| 6 |
(3)-15-[-1-(4-20)];
(4)(
| 1 |
| 3 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 10 |
| 10 |
| 3 |
(5)16÷(-2)-(-
| 1 |
| 8 |
(6)
| 1 |
| 1×2 |
| 1 |
| 2×3 |
| 1 |
| 3×4 |
| 1 |
| 1999×2000 |
(7)100+16÷(-2)4-
| 1 |
| 5 |
(8)-14-[2-(1-
| 1 |
| 3 |
分析:(1)先算同分母分数,再相加即可求解;
(2)直接运用乘法的分配律计算;
(3)有括号的先算括号里面的;
(4)先算括号里面的减法,再将除法变为乘法约分计算即可;
(5)(7)(8)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;
(6)先拆项,再抵消即可求解.
(2)直接运用乘法的分配律计算;
(3)有括号的先算括号里面的;
(4)先算括号里面的减法,再将除法变为乘法约分计算即可;
(5)(7)(8)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;
(6)先拆项,再抵消即可求解.
解答:解:(1)原式=(0.47+1.53)+(-4
-1
)
=2-6
=-4;
(2)原式=-
×30+
×30-
×30
=-27+2-5
=-30;
(3)原式=-15-[-1-(-16)]
=-15-(-1+16)
=-15-15
=-30;
(4)原式=-
×
×10×
=-
;
(5)原式=-8+
×16-1
=-8+2-1
=-7;
(6)原式=1-
+
-
+…+
-
=1-
=
;
(7)原式=100+16÷16-
×25-100
=100+1-5-100
=-4;
(8)原式=-1-[2-(1-
×
)]×[9-4]
=-1-[2-(1-
)]×5
=-1-1
×5
=-1-5
=-6
.
| 5 |
| 6 |
| 1 |
| 6 |
=2-6
=-4;
(2)原式=-
| 9 |
| 10 |
| 1 |
| 15 |
| 1 |
| 6 |
=-27+2-5
=-30;
(3)原式=-15-[-1-(-16)]
=-15-(-1+16)
=-15-15
=-30;
(4)原式=-
| 1 |
| 6 |
| 4 |
| 5 |
| 10 |
| 3 |
=-
| 40 |
| 9 |
(5)原式=-8+
| 1 |
| 8 |
=-8+2-1
=-7;
(6)原式=1-
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 1999 |
| 1 |
| 2000 |
=1-
| 1 |
| 2000 |
=
| 1999 |
| 2000 |
(7)原式=100+16÷16-
| 1 |
| 5 |
=100+1-5-100
=-4;
(8)原式=-1-[2-(1-
| 1 |
| 3 |
| 1 |
| 2 |
=-1-[2-(1-
| 1 |
| 6 |
=-1-1
| 1 |
| 6 |
=-1-5
| 5 |
| 6 |
=-6
| 5 |
| 6 |
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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