Dr. Stanley Schmidt has found a narrative way to teach math in Life of Fred. They're engaging, they're funny, and they really, really explain math concepts in a real-life way. The stories are about a boy named Fred (who also happens to be a math professor) and all his daily adventures. It's very hard to describe without making it sound ridiculous, so please look at the samples here.
What I love most about these books is that the lessons are really short. Dr. Schmidt has done a wonderful job of breaking the concepts down into bite-sized pieces, and breaking up the text with illustrations without making the pages too busy. After every five chapters there is a Bridge, which is a set of 10 review questions. You must get 9 out of the 10 questions correct before moving on to the next chapter. The nice thing is, though, that there are 5 sets of bridge questions, so if the students botches the first set, they can go back, correct their work, and begin again on the second set. So they have 5 tries at getting over the bridge!
There are 8 books in the series, ranging from pre-algebra to calculus. The first two books in the series are Fractions then Decimals & Percents. The subsequent books also have a teaching guide (Fred's Home Companion) to go along with them which includes a daily lesson schedule, all the solutions, plus more practice problems. My understanding is that you probably wouldn't need to have Fred's Home Companion for the advanced books in order to gain understanding of the concepts, but if you choose Life of Fred as your main math program and need to show substantial amounts of scheduled work for high school credit, you might want the extra problems and schedules.
Life of Fred would also make a very, very good review program for test prep and college placement. I wish I had had it before taking the math placement exam when I returned to college after an 18-year absence! Here's a word problem to illustrate:
Susan forgot all her higher math skills! When she decided to go back to school she had to take a math placement test. Because she did poorly (she hadn't taken math in almost 20 years!) she had to take a college review math class that cost $450 and did not even give her a math credit! The entire Life of Fred series (with Fred's Home Companion for 6 of the 8 books - 14 books in all) costs $302 (free shipping!). Which is the better value?
Answer: $302 < $450 (and much more fun)
Highly recommended for 6th grade and up.