Question

把下面分数化成百分数．
例：

1

2

=0.5=50%

1

4

=

0.25

=

25%

    

3

4

=

0.75

=

75%

    

1

5

=

0.2

=

20%

2

5

=

0.4

=

40%

   
 

3

5

=

0.6

=

60%

   
 

4

5

=

0.8

=

80%

1

8

=

0.125

=

12.5%

    

3

8

=

0.375

=

37.5%

   
 

5

8

=

0.625

=

62.5%

7

8

=

0.875

=

87.5%

．

Answer 1

分析：把分数化百分数，先用分数的分子除以分母得出小数商，除不尽时通常保留三位小数，再把小数点向右移动两位，同时填上百分号．

解答：解：

1

4

=0.25=25%

3

4

=0.75=75%

1

5

=0.2=20%

2

5

=0.4=40%

3

5

=0.6=60%

4

5

=0.8=80%

1

8

=0.125=12.5%

3

8

=0.375=37.5%

5

8

=0.625=62.5%

7

8

=0.875=87.5%．
故答案为：0.25，25%，0.75，75%，0.2，20%，0.4，40%，0.6，60%，0.8，80%，0.125，12.5%，0.375，37.5%，0.625，62.5%，0.875，87.5%．

点评：此题考查分数化百分数方法的灵活运用，熟记化法是解题关键．