题目内容
计算下列各题
(1)(5-6)-(7-9); (2)(-4
)-(+5
)-(-4
)
(3)22+(-4)+(-2)+4; (4)(-8)+(+0.25)-(-9)+(-
)
(5)(-81)÷2
; (6)(-3)×
×(-
)×(-
)
(7)(1-
+
)×(-48); (8)-1
÷
×(-0.2)×(-
)
(1)(5-6)-(7-9); (2)(-4
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 4 |
(3)22+(-4)+(-2)+4; (4)(-8)+(+0.25)-(-9)+(-
| 1 |
| 4 |
(5)(-81)÷2
| 1 |
| 4 |
| 5 |
| 6 |
| 4 |
| 5 |
| 1 |
| 4 |
(7)(1-
| 1 |
| 6 |
| 3 |
| 4 |
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 2 |
(1)(5-6)-(7-9)
=[5+(-6)]-[7+(-9)]
=-1-(-2)
=-1+2
=1;
(2)(-4
)-(+5
)-(-4
)
=(-4
)-5
+4
=(-4
)+4
-5
=-5
;
(3)22+(-4)+(-2)+4
=(22+4)+[(-4)+(-2)]
=26+(-6)
=20;
(4)(-8)+(+0.25)-(-9)+(-
)
=(-8)+(+0.25)+9+(-0.25)
=(-8)+9+[(+0.25)+(-0.25)]
=1+0
=1;
(5)(-81)÷2
=(-81)÷
=(-81)×
=-36;
(6)(-3)×
×(-
)×(-
)
=-3×
×
×
=-
;
(7)(1-
+
)×(-48)
=1×(-48)-
×(-48)+
×(-48)
=-48+8-36
=-84+8
=-(84-8)
=-76;
(8)-1
÷
×(-0.2)×(-
)
=-
×
×(-
)×(-
)
=-
×
×
×
=-1.
=[5+(-6)]-[7+(-9)]
=-1-(-2)
=-1+2
=1;
(2)(-4
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 4 |
=(-4
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 4 |
=(-4
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 3 |
=-5
| 1 |
| 3 |
(3)22+(-4)+(-2)+4
=(22+4)+[(-4)+(-2)]
=26+(-6)
=20;
(4)(-8)+(+0.25)-(-9)+(-
| 1 |
| 4 |
=(-8)+(+0.25)+9+(-0.25)
=(-8)+9+[(+0.25)+(-0.25)]
=1+0
=1;
(5)(-81)÷2
| 1 |
| 4 |
=(-81)÷
| 9 |
| 4 |
=(-81)×
| 4 |
| 9 |
=-36;
(6)(-3)×
| 5 |
| 6 |
| 4 |
| 5 |
| 1 |
| 4 |
=-3×
| 5 |
| 6 |
| 4 |
| 5 |
| 1 |
| 4 |
=-
| 1 |
| 2 |
(7)(1-
| 1 |
| 6 |
| 3 |
| 4 |
=1×(-48)-
| 1 |
| 6 |
| 3 |
| 4 |
=-48+8-36
=-84+8
=-(84-8)
=-76;
(8)-1
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 2 |
=-
| 3 |
| 2 |
| 4 |
| 3 |
| 1 |
| 5 |
| 5 |
| 2 |
=-
| 3 |
| 2 |
| 4 |
| 3 |
| 1 |
| 5 |
| 5 |
| 2 |
=-1.
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