According to the information you provided, there is still room for improvement beyond your mid-term exam total score of 299,500. However, to reach more than 500 points, you need to make great progress and performance in the following studies and exams.

Here are some suggestions to help you improve your total score:

Make a study plan: make a detailed study plan, including daily study time, study content and review plan. Arrange the time reasonably to ensure that all subjects have enough study time and review time.

Find a learning method that suits you: Different people have different learning methods. You need to find your own learning methods, such as taking notes, doing problems and reciting. Through effective learning methods, you can master knowledge faster and improve your grades.

Pay attention to the study of basic knowledge: the study of high school pays attention to the mastery of basic knowledge. If you don't have a solid foundation, it will be difficult to get good grades in the exam. So you need to pay attention to the study of basic knowledge and lay a solid foundation.

Do more exercises and mock exams: By doing more exercises and mock exams, you can improve your test-taking ability and skills, enhance your adaptability to exams and improve your test scores.

Establish good study habits: Good study habits can improve learning efficiency and quality, such as regular review, regular work and rest, and adherence to planning. By establishing good study habits, we can better improve our study level.

Finally, whether you can reach more than 500 points depends on your actual situation and study hard. If you can persist in studying hard and actively prepare for the exam, you have a chance to improve your total score.