I would have the student review 8x9 and 9x8 just to ensure that they realize that each problem has the same answer.
Next, student 2 has issues bringing down the proper numbers upon the first round of subtraction. This clearly is a result of misplacement. Placement is crucial in long division because if the student places the quotient in the wrong place, the entire problem is ruined! The third student has misplaced the quotient from the start and thus ruined his chances for a correct answer. This student too needs assistance in placement. He does, however have the mechanics in hand thus is in better shape than the second student.
The best way to verify the mistakes made by the students is to work out the problem with them. As the student is reviewing their work with you, you can gage whether the mistake was a chance happening or whether the student truly is not comprehending the task. Have the student multiply their incorrect quotient by the divisor and they will see it for themselves. Better yet, after the student has seen his/her error after the attempted multiplication of the quotient and divisor, have the student do the division problem with you and explain their steps to you as they do it.
The best way to correct the mistake presented in the three referenced problems is practice, practice and more practice.