The best solution. You don't have to worry that you can't do that. Just you try to open your heart and try not to use the phone if necessary. When it is time to time to be useful, such as homework.You need to set the rules in the class. If someone did to get punishment is if someone play phone while the teacher was teaching to seize the phone and money were 20 baht. After 1 hours return phone calls.Will the around money is 2 imaginable. And add hours to seize the phone. Just as you know to use the phone in a reasonable time.
The best way to solve this. Do you worry that you can not do. Just you try to open your mind and try not to use it unless necessary. When I have free time, it takes time to be useful, such as homework, but if you can not do. You must set up rules within the classroom. If you do not have to be punished is if you play phone while teachers are taught to hold the phone. And fined a total of 20 baht to one hour on the phone the night before. But if it is to play a second time. The money would be on a two-fold and add hours to hold the phone. Just as you know in a timely manner with the phone.