Students with a lack of self-discipline really need to evaluate whether the career path they've chosen is a good fit. Also, being a "student” requires skills that are not inherent to a lot of people.
If I find a student is slacking, I'll try to help them re-evaluate their commitment to the program, and make it clear that I'm as invested in their success as they are. If the student puts little effort in the program, so will I, as their teacher.
Then I'll gauge “student” skills by asking how they can show me that they are giving an honest effort in learning the material. If the student can identify those avenues, it often opens up those channels for communication and commitment.
As for math, If the student is comfortable, I'll ask the student to speak out loud their thought process on their approach to solving the math problem. This way, I can question their logic and help guide the student to solving the problem.
