Oh dear. When a student answers that 7/12 is 1.5 and doesn't immediately see why this couldn't possibly be true you know that the problem is rote learning of algorithms. Whoever gives such an answer does not connect classroom learning with the real world, he does not understand what the answer means. You see this often, even in university students. The problem isn't solved with more accountability or more teacher aut…
I saw this sort of thing a lot when I tutored physics in college. My students would crank through the formulas and come up with an answer. I would point out that their answer says the roller coaster is seventeen light years tall, or the bowling ball weighs less than a grain of sand, and this couldn't possibly be right. I always tried to get them to look at the shape of the problem first, and then look at the details. Otherwise you're just pattern matching, and don't know when you've gone horribly wrong.
It's tricky, though, because you need to strike a balance. Seeing the big picture really well doesn't get the job done if you don't have the mechanics to back it up. If the goal is a precise answer, then knowing that 7/12 is around 0.5 and is definitely not greater than 1 doesn't get you there. But it seems that schools have gone way too far the other way, focusing on the mechanics almost exclusively. The "word problem" seems to be the one concession to the big picture, but even those are taught as pure pattern-matching exercises.