We used LOF: Fractions as our main math curriculum and DS7 went from just thinking math was okay to *loving* it. He can't wait for us to start LOF: Decimals in the fall- we're doing logic/problem solving stuff for the summer. The story line completely captivated him and the fact that Fred was younger than he is really helped.
We did have to supplement with a fractions workbook (Success with Fractions 2 from prufrock.com) because he hadn't had any exposure to working with fractions. For an older kid who has actually done math through 6th grade, I would imagine the extra practice would be unnecessary. Fred is designed to be a total stand alone program and while the practice is fairly limited, it is designed to make the kids think about what they're doing and why rather than just memorize steps to solve problems. Though if you decide she does need the extra practice, I loved how Success with Fractions integrated with Fred and would recommend that.
As far as actual implementation, we did math 2-3x a week. We read the book together and talked about the chapter to make sure DS got what the author was trying to say. On the chapters that he quickly understood, we did the practice (Your Turn to Play) and then moved on. On the ones that he had a harder time, we slowed down and took a few days to go over the topic using the extra practice until he seemed comfortable with it. There were a few times when he had the mechanics of what he was supposed to do, but it wasn't until something later on was explained that he really got the reason behind it. We spent probably 3 months total on it, but we were going fairly slowly since so much of what we were doing was completely new to DS.
The lower level books aren't designed to be full year programs, but Fractions plus Decimals/Percents is roughly equivalent to a Pre-Algebra class. I also heard from Stan Schmidt that he's going to have the first of 3 Pre-Algebra books out at the end of the summer.
HTH!
