# 百分数

 以100作为分母的分数，称为百分数

${\displaystyle {\frac {83}{100}}}$ =83%

83%也是百分数，又称为百分率

 %(per cent) 称为百分号，表示1/100

83%读作：83per cent 或 83个百分点

 例题 题目: 83%是${\displaystyle {\frac {83}{100}}}$，90%是多少？ 解答: 90%是${\displaystyle {\frac {90}{100}}}$ O

 例题 题目: 全校有百分之二十的学生戴上口罩，即平均每100名学生中，便有多少名学生戴上口罩？ 解答: 20名 O
 例题 题目: 货品减价10%；表示原价平均每100元，便减价多少元？ 解答: 10元 O

(a)一成 = 1个${\displaystyle {\frac {1}{10}}}$ = ${\displaystyle {\frac {1}{10}}}$ (b)五成 = 5个${\displaystyle {\frac {1}{10}}}$ = ${\displaystyle {\frac {5}{10}}}$ (c)三成半 = 3.5个${\displaystyle {\frac {1}{10}}}$ = ${\displaystyle {\frac {3.5}{10}}}$ (d)八成半 = 8.5个${\displaystyle {\frac {1}{10}}}$ = ${\displaystyle {\frac {8.5}{10}}}$

★记著百分数的分母必须是100★

   =60/100
=60%


   =7.5×___/10×__
=_______/_______
=______________%

答案：75%



   =_______/_______
=______ /_______
=______________%

   答案=33%



${\displaystyle {\frac {8}{10}}}$

    = 8×10/10×10
= 80%


${\displaystyle {\frac {6.5}{10}}}$

      = 6.5×10/10×10
= 65%


★记著百分数的分母必须是100★

   ${\displaystyle {\frac {7}{10}}}$
= 7×10/7×10[/itex]
= 70%


   ${\displaystyle {\frac {9.5}{10}}}$
= ？×？/？×？}
= ____%

答案：95%


          答案：88%