题目内容
按特点与要求分拆:
+
+
+
+
+
+
+
+
=
| 1 |
| 7 |
| 3 |
| 8 |
| 7 |
| 36 |
| 29 |
| 56 |
| 37 |
| 63 |
| 41 |
| 72 |
| 53 |
| 77 |
| 29 |
| 84 |
| 3 |
| 88 |
考点:分数的巧算
专题:计算问题(巧算速算)
分析:根据分数的拆分原理和方法,把一个分数拆分成两个分数的和或差的形式,然后利用加法交换律和结合律进行简算.
解答:
解:
+
+
+
+
+
+
+
+
,
=
+
+(
-
)+(
+
)+(
+
)+(
+
)+(
+
)+(
-
)+(
-
),
=(
+
+
+
+
)+(
+
+
+
)+(
+
-
)+
-
+(
-
),
=1+1+(
+
-
)+
,
=1+1+1+
,
=3
.
| 1 |
| 7 |
| 3 |
| 8 |
| 7 |
| 36 |
| 29 |
| 56 |
| 37 |
| 63 |
| 41 |
| 72 |
| 53 |
| 77 |
| 29 |
| 84 |
| 3 |
| 88 |
=
| 1 |
| 7 |
| 3 |
| 8 |
| 3 |
| 4 |
| 5 |
| 9 |
| 1 |
| 7 |
| 3 |
| 8 |
| 1 |
| 7 |
| 4 |
| 9 |
| 1 |
| 8 |
| 4 |
| 9 |
| 1 |
| 7 |
| 6 |
| 11 |
| 3 |
| 7 |
| 1 |
| 12 |
| 1 |
| 8 |
| 1 |
| 11 |
=(
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 7 |
| 3 |
| 7 |
| 3 |
| 8 |
| 3 |
| 8 |
| 1 |
| 8 |
| 1 |
| 8 |
| 4 |
| 9 |
| 4 |
| 9 |
| 5 |
| 9 |
| 3 |
| 4 |
| 1 |
| 12 |
| 6 |
| 11 |
| 1 |
| 11 |
=1+1+(
| 3 |
| 9 |
| 3 |
| 4 |
| 1 |
| 12 |
| 5 |
| 11 |
=1+1+1+
| 5 |
| 11 |
=3
| 5 |
| 11 |
点评:此题考查的目的是掌握分数的拆分原理和方法,通过拆分达到简算的目的.
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