题目内容
计算下列各题,能简算的要简算
(1)
+(
-
)
(2)2-
-
(3)
-
+
(4)
+
+
+
(5)
-(
-
)
(1)
| 4 |
| 5 |
| 3 |
| 8 |
| 1 |
| 4 |
(2)2-
| 3 |
| 7 |
| 4 |
| 7 |
(3)
| 5 |
| 8 |
| 1 |
| 3 |
| 5 |
| 12 |
(4)
| 1 |
| 5 |
| 1 |
| 8 |
| 1 |
| 5 |
| 7 |
| 8 |
(5)
| 5 |
| 14 |
| 2 |
| 7 |
| 1 |
| 5 |
考点:分数的四则混合运算,分数的简便计算
专题:运算顺序及法则,运算定律及简算
分析:(1)(6)按照先算括号里面的,再算括号外面的顺序计算解答,
(2)运用减法性质解答,
(3)按照从左到右顺序计算解答,
(4)运用加法交换律和结合律解答.
(2)运用减法性质解答,
(3)按照从左到右顺序计算解答,
(4)运用加法交换律和结合律解答.
解答:
解:(1)
+(
-
)
=
+
=
;
(2)2-
-
=2-(
+
)
=2-1
=1;
(3)
-
+
=
+
=
;
(4)
+
+
+
=(
+
)+(
+
)
=
+1
=1
;
(5)
-(
-
)
=
-
=
.
| 4 |
| 5 |
| 3 |
| 8 |
| 1 |
| 4 |
=
| 4 |
| 5 |
| 1 |
| 8 |
=
| 37 |
| 40 |
(2)2-
| 3 |
| 7 |
| 4 |
| 7 |
=2-(
| 3 |
| 7 |
| 4 |
| 7 |
=2-1
=1;
(3)
| 5 |
| 8 |
| 1 |
| 3 |
| 5 |
| 12 |
=
| 7 |
| 24 |
| 5 |
| 12 |
=
| 17 |
| 24 |
(4)
| 1 |
| 5 |
| 1 |
| 8 |
| 1 |
| 5 |
| 7 |
| 8 |
=(
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 8 |
| 7 |
| 8 |
=
| 2 |
| 5 |
=1
| 2 |
| 5 |
(5)
| 5 |
| 14 |
| 2 |
| 7 |
| 1 |
| 5 |
=
| 5 |
| 14 |
| 3 |
| 35 |
=
| 19 |
| 70 |
点评:本题考查知识点:(1)依据四则运算计算方法正确进行计算,(2)正确运用简便方法解决问题.
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