It seems that simply bombarding the brain isn’t sufficient, even for language, and that social interaction is required (see this study), so that playing math games with the child would be a better idea.
How does the brain decide whether it thinks of something as a social interaction? I would assume that computer/video games with significant social components hack into that, so hacking into it to teach math should be doable.
I believe the way it works for language is that one can learn it from television, but not radio.
Nope. It needs to be something with feedback.
That makes intuitive sense, at least in hindsight, since TV provides ample non-linguistic information that you can learn to associate with the linguistic information.