题目内容
计算,能简便的用简便方法计算:
-
+
-
-(
-
)
5-
-
-
-(10-6)÷8.
| 8 |
| 17 |
| 7 |
| 15 |
| 26 |
| 17 |
| 8 |
| 15 |
| 5 |
| 6 |
| 7 |
| 15 |
| 5 |
| 12 |
5-
| 1 |
| 7 |
| 3 |
| 7 |
| 10 |
| 7 |
| 2 |
| 3 |
分析:①根据加法交换律和结合律先计算同分母分数;
②先计算括号里面的,再计算括号外面的;
③根据连减的简算方法计算;
④根据四则运算顺序和运算法则计算即可求解.
②先计算括号里面的,再计算括号外面的;
③根据连减的简算方法计算;
④根据四则运算顺序和运算法则计算即可求解.
解答:解:
-
+
-
,
=(
+
)-(
+
),
=2-1,
=1;
-(
-
)
=
-
=
;
5-
-
-
,
=5-(
+
+
),
=5-2,
=3;
-(10-6)÷8,
=
-4÷8,
=
-
,
=
.
| 8 |
| 17 |
| 7 |
| 15 |
| 26 |
| 17 |
| 8 |
| 15 |
=(
| 8 |
| 17 |
| 26 |
| 17 |
| 7 |
| 15 |
| 8 |
| 15 |
=2-1,
=1;
| 5 |
| 6 |
| 7 |
| 15 |
| 5 |
| 12 |
=
| 5 |
| 6 |
| 1 |
| 20 |
=
| 47 |
| 60 |
5-
| 1 |
| 7 |
| 3 |
| 7 |
| 10 |
| 7 |
=5-(
| 1 |
| 7 |
| 3 |
| 7 |
| 10 |
| 7 |
=5-2,
=3;
| 2 |
| 3 |
=
| 2 |
| 3 |
=
| 2 |
| 3 |
| 1 |
| 2 |
=
| 1 |
| 6 |
点评:考查了分数的四则运算,要熟练掌握分数四则运算顺序和运算法则,同时灵活运用运算律简便计算.
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