Algebra II Topics
http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/percentages/index.htm 

http://amby.com/educate/math/4-2_pr_x.html

http://www.mathgoodies.com/lessons/vol4/challenge_vol4.html

http://www.thegreatmartinicompany.com/percent-percentage/percent-is-of.html

http://www.thegreatmartinicompany.com/percent-percentage/percent-change.html

http://www.thegreatmartinicompany.com/percent-percentage/percent-is-of-bw.html

http://www.thegreatmartinicompany.com/percent-percentage/percent-is-of-bw.html

(percentage game)
http://www.mathplayground.com/percent_shopping.html

Simple Interest Rates

http://www.mathscore.com/math/practice/Simple%20Interest/

http://www.mathscore.com/math/free/lessons/Texas/8th_grade/Simple_Interest_sample_problems.html

http://algebralab.org/Word/Word.aspx?file=Algebra_InterestI.xml

http://www.aaamath.com/g84-simple-interest.html

Challenge problems interest

http://gmat.jumbotests.com/tests/gmat-simple-interest

http://www.montgomerycollege.edu/faculty/~jriseber/public_html/wquiz3-1c.htm

http://www.montgomerycollege.edu/faculty/~jriseber/public_html/wquiz3-1c.htm

http://www.mathwarehouse.com/compound-interest/formula-calculate.php

http://www.algebralab.org/Word/Word.aspx?file=Algebra_InterestII.xml

http://www.mathwarehouse.com/compound-interest/continuously-compounded-interest.php