When my kids were little, age 2 or 3, I put up big addition table and multiplication table posters in their rooms. I didn't tell them what to do with them; in fact, I didn't mention them at all. But by the time they were ready for school, they knew both their addition facts and multiplication tables. My daughter by age 9 was saying things to me like, "Mom, did you know that all the 9s are made up of numbers that add up to nine?" "Mom, did you know all those numbers have patterns?"
Parents may not be able to afford private schooling, or want to homeschool, but they can make some big preemptive strikes by doing similar things. Then, when the little darlings get into school, they already know the stuff.
I also put up posters of the US Presidents, the Constitution, Gettysburg Address, US Map with state names and capitals, etc. They figured out what to do with the information.
great idea!