解:(1)

=0.5=50%;
(2)

=0.25=25%;
(3)

=0.75=75%;
(4)

=0.2=20%;
(5)

=0.4=40%;
(6)

=0.6=60%;
(7)

=0.8=80%;
(8)

=0.125=12.5%;
(9)

=0.375=37.5%;
(10)

=0.625=62.5%;
(11)

=0.875=87.5%;
(12)

=0.1=10%.
故答案为:50%,25%,75%,20%,40%,60%,80%,12.5%,37.5%,62.5%,87.5%,10%.
分析:分数化百数,分母是100的分数,直接改写成百分数号即可,即去掉分母,添上百分号(%);一般分数化百分数,首先把分数化成小数,再把小数点向右移动两位,添上百分号(%)即可,如果不能化成有限小数,根据需要取近似值,一般百分号前保留一位小数.
点评:本题是考查分数化百分数,属于基础知识,必须掌握.