I am a basic skills program director at a community college; it so happens I direct curriculum in this area.
Yes, I can vouch for the Khan Academy lessons. My Intensive GED Prep students use them and they are a bit more interesting than drill-and-kill. If you need some homework-style drills to practice skills, try aaamath.com
is another site we use as well. Both of those sites are free.
For a little bit of money, you could buy a membership to IXL, which is the main math curriculum we use in my program (www.ixl.com
). It's $10 a month or $80 a year, but it covers everything from basic number sense to college-level algebra. Our math instructors use it in a module approach, where a student has to work through the modules in a self-paced mode, and score 80% or better in each module to be considered proficient.
The other thing I would stress to anyone struggling with math proficiency is to really hammer down on the basics of the four functions. Single-digit addition and subtraction needs to be automatic and reflexive. Multiplication and division tables up to 12 should also be automatic, as well as a clear understanding of how to shortcut using factors of 10 and "chopping up" multiple-digit multiplication into smaller equations. Once that becomes second nature, the difficulty really falls away from most other mathematical tasks.
PM me with specifics if you like. Best of luck to you!