KTPie, Ixl aligns nicely with common core and our public school district uses it starting at k level. I used that site for dd4.5 6 months ago and she started at 1st grade and completed it fairly quickly. Then she went to 2nd grade and got real bored with the repetition. Plus she really enjoys using math to solve problems instead of just doing the operations. So we stopped. Now we use Singapore math workbooks and Flash kids workbook for gifted kids and for most parts she can work independently. Unlike your kid, dd is not advanced in reading so I still have to read her some of the problems. So if you are okay with paper math instead of online, this might work.
