试题

题目:
计算:
(1)0-(+5)-(-3.6)+(-4)
(2)-14-
1
6
×[3-(-3)2]
(3)(
3
8
-
1
6
-
3
4
)×(-24)
(4)(-
1
3
)
2
÷
1
33
-12×(
2
3
-
1
6

(5)49
14
15
×(-5)(简便运算)
答案
解:(1)0-(+5)-(-3.6)+(-4)
=0-5+3.6-4
=-9+3.6
=-5.4;

(2)-14-
1
6
×[3-(-3)2]
=-1-
1
6
×(3-9)
=-1-
1
6
×(-6)
=-1+1
=0;

(3)(
3
8
-
1
6
-
3
4
)×(-24)
=
3
8
×(-24)-
1
6
×(-24)-
3
4
×(-24)
=-9+4+18
=22-9
=13;

(4)(-
1
3
2÷
1
33
-12×(
2
3
-
1
6

=
1
9
×27-12×
1
2

=3-6
=-3;

(5)49
14
15
×(-5)
=(50-
1
15
)×(-5)
=50×(-5)-
1
15
×(-5)
=-250+
1
3

=-249
2
3

解:(1)0-(+5)-(-3.6)+(-4)
=0-5+3.6-4
=-9+3.6
=-5.4;

(2)-14-
1
6
×[3-(-3)2]
=-1-
1
6
×(3-9)
=-1-
1
6
×(-6)
=-1+1
=0;

(3)(
3
8
-
1
6
-
3
4
)×(-24)
=
3
8
×(-24)-
1
6
×(-24)-
3
4
×(-24)
=-9+4+18
=22-9
=13;

(4)(-
1
3
2÷
1
33
-12×(
2
3
-
1
6

=
1
9
×27-12×
1
2

=3-6
=-3;

(5)49
14
15
×(-5)
=(50-
1
15
)×(-5)
=50×(-5)-
1
15
×(-5)
=-250+
1
3

=-249
2
3
考点梳理
有理数的混合运算.
(1)先写成省略加号的形式,再根据有理数的加减混合运算进行计算即可得解;
(2)先算乘方与括号,再算乘法,最后算加减即可;
(3)利用乘法分配律进行计算即可得解;
(4)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,有括号先算括号里面的;
(5)把49
14
15
写成(50-
1
15
),然后利用乘法分配律进行计算即可得解.
本题考查了有理数的混合运算,注意运算顺序:有乘方先算乘方,再算乘除,最后算加减,有括号项算括号里面的,运用运算定律使运算更加简便.
计算题.
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