Well, not knowing what the rules of the game are supposed to be, it is difficult to tell what you are doing wrong in your methods.
I agree with you however; you do need to tidy it up. You have capitalisation wrong, you have some if . . . {} blocks all written as one line, you seem to be creating your Scanner object and a dice() object several times.
You don't need the java.math.*; import; you aren't using either of the java.math classes. And if I say any more, I shall expect you to share the marks with me