This paper (actually three short articles) describes Louis Benezet's now-80-year-old experiment to delay the teaching of formal arithmetic until grade 7. This article has been the subject of much debate over the years, and (as far as I know) there has been no real modern equivalent; I'm interested to know: what do you all think?
In the spirit of open discussion, I'll hold off on giving my own opinion until down in the comments; hopefully this will let those who are not familiar with this article read it relatively free of bias.
I find this fascinating. I do think that we should really implement this, not only with one language, but we should start teaching foreign languages to kids as soon as possible, not only focusing on one language.