please check out the weblinks on this thread:
you can get lots of problems you can work for free along with step-by-step solutions on a textbook companion website by addison pearson publishing that publishes math textbooks called interactmath.com (http://www.interactmath.com/
). you have to follow the instructions to download two driver programs in order to use the software on the website as well as choose a textbook. for your purposes choose a pre-algebra textbook, preferably one by author martin-gaye. this is the only website i know of where you can get loads of free problems to work. most of the other websites on the internet you will have to pay for practice worksheets.