题目内容
(2012?仪征市)分子是1的分数,叫单位分数.古代埃及人在进行分数运算时,只使用分子是1的分数,因此这种分数也叫做埃及分数.
例如:
=
+
=
+
+
请你填写
=
+
=
+
=
+
=
+
.
例如:
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
| 17 |
| 18 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 9 |
| 1 |
| 6 |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
| 1 |
| ( ) |
分析:此题实际上是把一个较大的分数单位拆成两个较小的分数单位的和,因此,可以先把分母分解成两个因数的积,或者把这个分数的分子和分母扩大相同的倍数,然后根据分数的基本性质,给分数的分子和分母同时乘这两个分数的和,再把它拆成两个分数相加的和,并把每个加数进行约分.
解答:解:
=
=
=
+
=
+
;
=
=
=
+
=
+
;
=
=
=
=
+
=
+
;
=
=
=
+
=
+
;
因此
=
+
=
+
=
+
=
+
.
| 1 |
| 6 |
| 1 |
| 2×3 |
| 1×(2+3) |
| 2×3×(2+3) |
| 2 |
| 6×5 |
| 3 |
| 6×5 |
| 1 |
| 15 |
| 1 |
| 10 |
| 1 |
| 6 |
| 1 |
| 1×6 |
| 1×(1+6) |
| 1×6×(1+6) |
| 1 |
| 6×7 |
| 6 |
| 6×7 |
| 1 |
| 42 |
| 1 |
| 7 |
| 1 |
| 6 |
| 2 |
| 12 |
| 2 |
| 6×2 |
| 2×(6+2) |
| 6×2×(6+2) |
| 12 |
| 12×8 |
| 4 |
| 12×8 |
| 1 |
| 8 |
| 1 |
| 24 |
| 1 |
| 6 |
| 3 |
| 18 |
| 3×(3+6) |
| 3×6×(3+6) |
| 9 |
| 18×9 |
| 18 |
| 18×9 |
| 1 |
| 18 |
| 1 |
| 9 |
因此
| 1 |
| 6 |
| 1 |
| 15 |
| 1 |
| 10 |
| 1 |
| 42 |
| 1 |
| 7 |
| 1 |
| 14 |
| 1 |
| 6 |
| 1 |
| 18 |
| 1 |
| 6 |
点评:此题主要考查学生学习了“分数的基本性质、分数加减法的计算方法”等知识后,运用有关知识解答有一定思维难度的数学问题的能力.
练习册系列答案
相关题目