Thanks, have another technique question. How do you loosen up a person's hands? I have another girl with a very awkward playing position in her hands and haven't quite come up with a good way of loosening her up. Suggestions are appreciated.
I don't know if this will help, but here's an exercise one of my teachers had me do once:
Put both hands flat on a table, palms down, all five fingers tightly together (parallel). Then, keeping the hands flat on the table, spread the fingers out as far as they will go. Then tightly together again. Alternate between the two positions. Once comfortable with this, do the exercise in the air (i.e. away from the table) but with the hands still retaining their flat shape. Then do the alternating much more slowly, gradually and smoothly moving from the together to the apart position and back, taking about 10 seconds to move from one extreme to the other, counting the seconds out loud. The idea is to learn how to make your muscles control hand shape.
A similar exercise could be used to change fingers between flat and curled.
Perhaps get her to stand up and let her arms dangle by her side, totally relaxed, with all the arm and hand muscles "switched off". Her hands should now be loose. She can then sit, keeping her arms dangling. Then get her to lift her elbow up sideways until almost level with the shoulders while her forearm and hand are still relaxed and hanging vertically. Use the upper arm like a crane to deposit the loose hand onto the table at which she is sitting. The aim is to get the hand to "land" in close to a playing position, but still totally relaxed.
Looking back over this thread, I don't know if I understand your question about thumbs. Are you saying the pupils are holding their hands so that their fingers (2-5) are resting on the white keys so near the edge of the keyboard that their thumbs are off the edge and dangling in the air? If so, get them to move their hands further forward "into" the keyboard, so that the thumbs can also rest on the keys. If their fingers are then in danger of colliding with the black keys, then they are probably stretched out flat, which is to be discouraged. They should not be like spider legs, but should be curled, like a claw, so that the fingertips are more or less at right angles to the keys. That way they have both more power and more control.
Cut out a piece of paper about 4.5 inches by 1.5 inches and lay it on a table, then get them to put their fingers on the table such that all five fingers are on the piece of paper.
As for the grading thing, try to make them understand that the grading is objective; it's a description of where they're at. A good grade isn't a favour you do for them, for which in turn they may like you. A poor grade is not necessarily a bad thing, at least not to start with. It is an opportunity for improvement. Tell them that your job as a teacher is to make your pupils better, and that means their grades have to improve over time, but they can't improve unless they start low. Bust the myth that good grades are a reward for the hard work of practising. The real reward for hard work is that they become better players, and grades are just a measure of that.