Yeah, I know...should have been more clear about the rules. You lose when the game calculates that no matter what moves you make next you would not be able to win.
Also, the number split when there's a difference between the card number and the Q number, so let's say the Q have 7 left and you play it against a 10, the 10 would then be a 3. But you are right, it's very confusing the way it tries to teach you that, sorry haha