题目内容
| 计算下面各题,能简便的要简便. ①
| ②
| ③
| ④
| ||||||||||||||||||||||||||
⑤3-
| ⑥
| ⑦
| ⑧
|
考点:分数的四则混合运算
专题:运算顺序及法则
分析:①②按从左到右的顺序计算即可.
③可根据加法交换律与结合律计算.
④可根据加法交换律计算.
⑤可根据一个数减两个数,等于用这个数减去这两个数的和减法性质计算.
⑥先算括号里减法,再算加法.
⑦可先算括号中减法,再算加法.
⑧先算括号里减法,再算括号外减法.
③可根据加法交换律与结合律计算.
④可根据加法交换律计算.
⑤可根据一个数减两个数,等于用这个数减去这两个数的和减法性质计算.
⑥先算括号里减法,再算加法.
⑦可先算括号中减法,再算加法.
⑧先算括号里减法,再算括号外减法.
解答:
解:①
+
+
=
+
=
;
②
-
+
=
+
=
;
③
+
+
+
=(
+
)+(
+
)
=
+2
=2
;
④
-
+
=
+
-
=1-
=
;
⑤3-
-
=3-(
+
)
=3-1
=2;
⑥
+(
-
)
=
+
=
;
⑦
+(
-
)
=
+
=
;
⑧
-(
-
)
=
-
=
.
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
=
| 5 |
| 4 |
| 5 |
| 6 |
=
| 25 |
| 12 |
②
| 5 |
| 4 |
| 5 |
| 8 |
| 7 |
| 12 |
=
| 5 |
| 8 |
| 7 |
| 12 |
=
| 29 |
| 24 |
③
| 2 |
| 9 |
| 9 |
| 8 |
| 5 |
| 9 |
| 7 |
| 8 |
=(
| 2 |
| 9 |
| 5 |
| 9 |
| 7 |
| 8 |
| 9 |
| 8 |
=
| 7 |
| 9 |
=2
| 7 |
| 9 |
④
| 3 |
| 5 |
| 3 |
| 10 |
| 2 |
| 5 |
=
| 3 |
| 5 |
| 2 |
| 5 |
| 3 |
| 10 |
=1-
| 3 |
| 10 |
=
| 7 |
| 10 |
⑤3-
| 3 |
| 7 |
| 4 |
| 7 |
=3-(
| 3 |
| 7 |
| 4 |
| 7 |
=3-1
=2;
⑥
| 5 |
| 13 |
| 7 |
| 9 |
| 1 |
| 9 |
=
| 5 |
| 13 |
| 2 |
| 3 |
=
| 41 |
| 39 |
⑦
| 1 |
| 14 |
| 4 |
| 7 |
| 7 |
| 14 |
=
| 1 |
| 14 |
| 1 |
| 14 |
=
| 1 |
| 7 |
⑧
| 2 |
| 9 |
| 3 |
| 4 |
| 2 |
| 3 |
=
| 2 |
| 9 |
| 1 |
| 12 |
=
| 5 |
| 36 |
点评:完成本题要注意分析式中数据的特点,然后运用合适的方法计算.
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