so, you'll walk in and buy a can of soup at dollarama that is 10% less than retail and think you got a deal, without realizing it's 25% smaller. they do this for everything they can package, and it is rare that you're saving money; you're usually actually overpaying.
but you can't tell that if you lack grade school numeracy and cannot do basic math in your head, which is the sad truth for many canadians.