In many countries it is common for teenagers to take part-time jobs while they are still in high school, while in other societies this is virtually unheard of. In the latter situation, students are expected to spend all of their time on their studies and consider schoolwork their "job". In my opinion, students benefit more from a more balanced lifestyle, which may include working at a part-time job. Therefore, I believe that it is a good idea for students to work while studying.
While it is true that a student's most important goal must be to learn and to do well at his studies, it does not need to be the only goal. In fact, a life which consists of only study is not balanced and may cause the student to miss out on other valuable learning experiences. In addition to bringing more balance to a student's life, part-time work can broaden his range of experience. He will have the opportunity to meet people from all walks of life and will be faced with a wider variety of problems to solve. Furthermore, work helps a student to develop greater independence, and earning his own pocket money can teach him how to handle his finances. Finally, a part-time job can help a student to develop a greater sense of responsibility, both for his own work and for that of the team he works with.
For all of these reasons, I firmly believe that most students would benefit from taking a part-time job while they are in high school. Of course, they must be careful not to let it take up too much of their time because study is still their primary responsibility. In sum, living a balanced life is the best way to be successful.