I can agree with David Park that anyone who learns maths in the US (unless you are very lucky) more or less has to do it on their own. There were some exceptional teachers at Wolfram Technology conferences who used Mathematica very effectively for high school and college, but it was clear that these are exceptions.
You might check out Jo Boaler or Keith Devlin. They have a presence on the web, and they have been working in this area for quite a while. Dr. Devlin has a MOOC: Introduction to Mathematical Thinking, which is worth taking. Any student in middle school or beyond could do the work, and any parent who wants to provide a suitable environment for learning could benefit as well. Dr. Boaler has a website (http://www.youcubed.org) with a lot of excellent material, and also teaches a MOOC. If you do any reading at all about maths education, you will find that it is a mine field.
You did not mention how old your children are. For young children, I think that a hands-on approach, anther than immediately going to the computer is likely to be effective. Playing with ZomeTool, Cuisenaire rods, ore even legos (in their plain varieties) can help with an intuitive understanding of what maths is about. Making the connection between maths and science is also essential at this age (K-6), but a lot of schools have neglected science in elementary school because sit is not being tested. Most of maths arose either from science or finance, and these practical activities -- making change, doing simple experiments -- probably do more to allow children to learn maths than any amount of drill and kill.
There is a lot on the web about computer based maths -- Wolfram research is involved in this. I think that learning to code is a great activity in general, and as a replacement for typical drill-and-kill activities in the classroom. Mathematica can be an excellent first language, but it can be very intimidating. I was already an adult when I learned to program in 1970, and people were pleased if you could do anything at all -- not like today. BASIC on a time-sharing system was how I (and Bill Gates and a lot of other people) learned how to program. Of course, I already had a maths degree by that time, so solving scientific problems in code was not that hard. Mathematica has some of the flavor of my early experience, in that a learner can do some really elegant things right away. The task for the teacher or parent is to see that some maths is learned along the way.
I just finished a book "How not to be Wrong" by Jordan Ellenberg. I think anyone interested in maths -- and a lot of people who think that they don't do maths -- should read this book.
If you do chose to go down this path, it is likely that you will have to contend with the system. Students will need to satisfy the requirements of the school system to get the grades they need to get into a decent school, and then do the extra work to actually learn maths.
good luck.