My son has used it and went from a 21 to a 27 (with a 29 in English and 30 in Math). What I like about it is that when you get an answer wrong you can review the question and it gives a detailed explanation why a particular answer was wrong and why a particular answer is the best answer. It is just like anything else though; you have to put some time into to get better. Just remember -- “The dictionary is the only place that success comes before work. Hard work is the price we must pay for success. I think you can accomplish anything if you're willing to pay the price." - Vince Lombardi