题目内容
脱式计算.(能简算的要简算)
+
+
+(
-
)
+
-
2-
-
.
| 5 |
| 12 |
| 7 |
| 8 |
| 7 |
| 12 |
| 5 |
| 16 |
| 4 |
| 5 |
| 5 |
| 16 |
| 1 |
| 4 |
| 5 |
| 8 |
| 1 |
| 2 |
2-
| 13 |
| 27 |
| 8 |
| 27 |
考点:分数的简便计算
专题:运算定律及简算
分析:(1)运用加法的结合律进行计算;
(2)先把括号去掉,再把
减去
后再与
相加简算;
(3)先通分,然后从左往右进行计算;
(4)运用减法的性质进行计算.
(2)先把括号去掉,再把
| 5 |
| 16 |
| 5 |
| 16 |
| 4 |
| 5 |
(3)先通分,然后从左往右进行计算;
(4)运用减法的性质进行计算.
解答:
解:(1)
+
+
=(
+
)+
=1+
=1
(2)
+(
-
)
=
-
+
=
(3)
+
-
=
+
-
=
(4)2-
-
=2-(
+
)
=2-
=1
| 5 |
| 12 |
| 7 |
| 8 |
| 7 |
| 12 |
=(
| 5 |
| 12 |
| 7 |
| 12 |
| 7 |
| 8 |
=1+
| 7 |
| 8 |
=1
| 7 |
| 8 |
(2)
| 5 |
| 16 |
| 4 |
| 5 |
| 5 |
| 16 |
=
| 5 |
| 16 |
| 5 |
| 16 |
| 4 |
| 5 |
=
| 4 |
| 5 |
(3)
| 1 |
| 4 |
| 5 |
| 8 |
| 1 |
| 2 |
=
| 2 |
| 8 |
| 5 |
| 8 |
| 4 |
| 8 |
=
| 3 |
| 8 |
(4)2-
| 13 |
| 27 |
| 8 |
| 27 |
=2-(
| 13 |
| 27 |
| 8 |
| 27 |
=2-
| 7 |
| 9 |
=1
| 2 |
| 9 |
点评:此题主要考查分数的四则混合运算的运算顺序,以及应用运算定律进行简便计算的能力.
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