Abeka Christian Homeschooling curriculum. They've been doing it since 1972, it's awesome. I don't think it's very cheap, but it's worth it. I was homeschooled up till 4th grade at which point I went to a private school which based most of its curriculum on Abeka and but added from others. Today that school is one of the top in the state. I've no idea if they still use Abeka, I would assume they do, but I have family members whose kids go there, it's top tier in almost everything.