you may want to ask Matt_24_24 about this becuase i think he goes to UofA.
your school uses the US GPA scale. Howevever, normally GPA's are calculated based on letter grades - so, your GPA will stand as is...
It might seem unfair (ie. how come your school has 84=A and mine is 84=B), but depends on the class averages. Canadian schools grade on a curve and normally class average is C+/B-. So at you school, average is around 80%. But take UofT, the class average is around 67% ... so comparing the GPA's is "fair".