The students addition book is available on-line at: http://www.glencoe.com/sec/math/ose/index.html
User Name: MAC3TN05
Password: ST6zedAv
Also, in the book there are additional examples of problems in the back of the book.
Plus, on-line at: http://www.glencoe.com/sec/math/msmath/mac04/course3/index.php/tn/2004
there are another set of additional problems related to the same problems in each section and there are practice tests and quizzes for the chapters and TCAP.