You could look at ALEKS.com.
ALEKS FOR INDEPENDENT USE
ALEKS is a research-based, online program that offers course products for mathematics, business, science, and behavioral science. Using personalized learning and adaptive assessments, ALEKS quickly and accurately determines exactly what a student is most ready to learn. This unique approach to learning dramatically improves student performance and confidence.
ALEKS offers a robust course library for use by parents, students, homeschoolers, and tutors.
It is now owned by McGraw hill ....hope they haven't ruined it.
