试题

题目:
计算:
(1)-2-3-5
(2)(-2)÷
1
3
×(-3)

(3)(
2
3
-
1
12
-
4
15
)×(-60)

(4)-14+8-23÷(-4)×(-7+5)
(5)100-(-3)÷(
3
4

(6)-11-2×(-33)+(-22)
(7)-32÷[-32-(-2)3].
答案
解:(1)-2-3-5
=-(2+3+5)
=-10;

(2)(-2)÷
1
3
×(-3)

=-6×(-3)
=18;

(3)(
2
3
-
1
12
-
4
15
)×(-60)

=-
2
3
×60+
1
12
×60+
4
15
×60
=-40+5+16
=-19;

(4)-14+8-23÷(-4)×(-7+5)
=-1+8-8÷(-4)×(-2)
=-1+8-4
=3;

(5)100-(-3)÷(
3
4

=100+4
=104;

(6)-11-2×(-33)+(-22)
=-11-66-22
=-99;

(7)-32÷[-32-(-2)3]
=-32÷[-9+8]
=-32÷[-1]
=32.
解:(1)-2-3-5
=-(2+3+5)
=-10;

(2)(-2)÷
1
3
×(-3)

=-6×(-3)
=18;

(3)(
2
3
-
1
12
-
4
15
)×(-60)

=-
2
3
×60+
1
12
×60+
4
15
×60
=-40+5+16
=-19;

(4)-14+8-23÷(-4)×(-7+5)
=-1+8-8÷(-4)×(-2)
=-1+8-4
=3;

(5)100-(-3)÷(
3
4

=100+4
=104;

(6)-11-2×(-33)+(-22)
=-11-66-22
=-99;

(7)-32÷[-32-(-2)3]
=-32÷[-9+8]
=-32÷[-1]
=32.
考点梳理
有理数的混合运算.
(1)根据有理数的减法法则计算即可;
(2)按照从左往右的顺序计算即可;
(3)直接运用乘法的分配律计算;
(4)(7)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;
(5)(6)按照有理数混合运算的顺序,先乘除后算加减,有括号的先算括号里面的.
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-.
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