FWIW, Khan Academy is pretty well aligned with Common Core, at least in terms of material covered: https://www.khanacademy.org/commoncore/map

I think a lot of what people complain about with Common Core is bizarrely written school materials that were developed by some bureaucracy and don't make a whit of sense to an adult who already knows the skill, let alone to a kid. Khan Academy definitely does better on that count in my opinion, so it's a good supplement.

> Far better than that Common Core nonsense.

You should check out Khan Academy because it's well aligned to the Common Core. The general effect of the CA Common Core was advance the math curriculum by about 6 months.

What exactly do you have against common core?

Many people have conflated Common Core (a set of objectives of what should be learned and by when, generally pretty good) with the materials that came out to support it from textbook publishers and others (pretty shitty).