That does not explain why Alberta, which apparently has far higher standards at 6th grade than Ontario based on the online questions, only has about 25% of grade 6 students fail its tougher standards.

If it's not due to teaching then the only other thing I can think of is that Albertans must be naturally smarter than Ontarians and while I don't think that's the case I'm certainly not going to stop you if you want to make that argument! ;-)