I came across NeoK12 due to a tweet from MamaByNature. My kids are already hooked – my 4 year old watched a video on subtraction on it and was quickly asking for help on using his fingers to do a little subtraction.
The site contains videos on all sorts of educational topics. Anything too advanced for the kids you can always watch together and discuss. There are plenty of science, math, English and social studies videos to choose from.
It’s not all serious either. My oldest loves the magic tricks section, where videos explain how the tricks are done. There are also time lapse videos, arts & crafts, music and sports videos.