It is harmful and helpful for a middle school student to take mobile phones. First of all, if we have mobile phones, we can contact our friends and parents anytime and anywhere. We can also use mobile phones to surf the Internet.
When we are not at home, parents can find us. But playing with mobile phones may have some bad things, which may affect students' grades and reduce their interest in learning. Moreover, many students cheat on their mobile phones in exams, which is definitely not a good thing.
A mobile phone may cost a lot of money, but as students, we don't make money by "calling".