Why 90% of Hogwarts Graduates are Functionally Illiterate

Seriously, though, do the books ever address the fact that Hogwarts School of Witchcraft and Wizardry doesn't ever teach anyone how to spell? I mean, kids get enrolled at the age of, what, 11? Doesn't that mean that Harry Potter never progressed past that point in literacy or math?

Maybe all the spells are in Latin because it's phonetically easier to read when you're functionally illiterate!

Notice how when Albus Dumbledore talks about how old Hogwarts is, he just says that it's been around for over one thousand years? I'm willing to bet the year of foundation is well known, it's just that he can't do the math to calculate the school's age!