题目内容
计算:(1)1-2;
(2)-[-(0.2)2+
| 1 |
| 25 |
| (-3)2 |
| 4 |
(3)[-3÷(-
| 3 |
| 2 |
| 3 |
| 4 |
| 3 |
| 8 |
(4)(-
| 1 |
| 4 |
| 1 |
| 2 |
| 3 |
| 8 |
| 1 |
| 3 |
| 3 |
| 4 |
分析:(1)运用减去一个数等于加上这个数的相反数,变为加法再计算;
(2)(3)(4)按照有理数混合运算的顺序,有括号先算括号里面的,再按照先乘方,后乘除,最后算加减的顺序进行,注意运用乘法的分配律简化计算.
(2)(3)(4)按照有理数混合运算的顺序,有括号先算括号里面的,再按照先乘方,后乘除,最后算加减的顺序进行,注意运用乘法的分配律简化计算.
解答:解:(1)1-2=1+(-2)=-1;
(2)原式=-(-0.04+0.04)+(8-9×1)×
=-1×
=-
;
(3)原式=(-3×
-4×
+1×
)÷|2×
-
|×2
=(-
-
+
)÷|
-
|×2
=-
×4×2
=-4;
(4)原式=
×16×1-(-
×24+
×24-
×24)
=4-(-9+56-90)
=4+9-56+90
=47.
(2)原式=-(-0.04+0.04)+(8-9×1)×
| 4 |
| 9 |
=-1×
| 4 |
| 9 |
=-
| 4 |
| 9 |
(3)原式=(-3×
| 4 |
| 9 |
| 1 |
| 8 |
| 4 |
| 3 |
| 25 |
| 16 |
| 27 |
| 8 |
=(-
| 4 |
| 3 |
| 1 |
| 2 |
| 4 |
| 3 |
| 25 |
| 8 |
| 27 |
| 8 |
=-
| 1 |
| 2 |
=-4;
(4)原式=
| 1 |
| 16 |
| 3 |
| 8 |
| 7 |
| 3 |
| 15 |
| 4 |
=4-(-9+56-90)
=4+9-56+90
=47.
点评:有理数混合运算的顺序,有括号先算括号里面的,再按照先乘方,后乘除,最后算加减的顺序进行,注意运用运算律简化计算.
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