题目内容
简算:
+
+
+
+
+
+
+
+
+
.
| 1 |
| 7 |
| 3 |
| 8 |
| 7 |
| 36 |
| 29 |
| 56 |
| 37 |
| 63 |
| 41 |
| 72 |
| 53 |
| 77 |
| 29 |
| 84 |
| 29 |
| 84 |
| 3 |
| 88 |
考点:分数的巧算
专题:计算问题(巧算速算)
分析:通过观察,此题如果通分计算会很麻烦,因此应运用拆分的方法,根据加法结合律简算.
解答:
解:
+
+
+
+
+
+
+
+
+
=
+
+(
-
)+(
+
)+(
+
)+(
+
)+(
+
)+(
-
)+(
-
)
=(
+
+
+
+
)+(
+
+
+
)+(
+
-
)+
-
+(
-
)
=1+1+(
+
-
)+
=3
| 1 |
| 7 |
| 3 |
| 8 |
| 7 |
| 36 |
| 29 |
| 56 |
| 37 |
| 63 |
| 41 |
| 72 |
| 53 |
| 77 |
| 29 |
| 84 |
| 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 |
| 3 |
| 7 |
| 1 |
| 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 |
=3
| 5 |
| 11 |
点评:此题主要考查学生能否根据数字特点,通过转化的数学思想,巧妙灵活地运用运算技巧,使复杂的问题简单化.
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