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%.
故答案為:50%,25%,75%,20%,40%,60%,80%,12.5%,37.5%,62.5%,87.5%,10%.
分析:分數化百數,分母是100的分數,直接改寫成百分數號即可,即去掉分母,添上百分號(%);一般分數化百分數,首先把分數化成小數,再把小數點向右移動兩位,添上百分號(%)即可,如果不能化成有限小數,根據需要取近似值,一般百分號前保留一位小數.
點評:本題是考查分數化百分數,屬于基礎知識,必須掌握.