shut it off, smash it, tie a brick to it and toss it into a river. but don't worry.. one day your homework will probably be on your Iphone and you kids will never have to lift your heads from the screen and see the real world again!
I would hand over my phone right away to my mom or dad and tell then not to give it back until the next morning (or when all work is done). Remember to turn off the power so your parents don't read texts or get phone calls from your friends.
Also if you have homework using the computer, make a list of what you need to search or research so you don't get distracted from advertisements or websites. Also signing out of social media sites will make you less distracted.