My son (just turning 7) is smarter than I am; and possibly more as an artifact of being on the spectrum, is nearly bored after textual representations ( one tredecillion, ten tredecillion...), ~70 digits of pi, latin/greek alphabet, periodic table, planets/cosmos, and every other aspect of rote memorable/science/math things.
I'm not sure if he's bored now, or simply too busy with trying to learn to read, or burnt out, but I've tried to look for more collegiate material that may suit him, besides looking ahead 4-5 school years, and come up rather short. Some private tutoring material has seemed most helpful, but so far, YouTube has the best material, but obviously that has its own issues.
Besides more moderated Youtube/Kids, i fear im missing something obvious