A powerful reward is a phone call to mum/dad in front of the class. I have used this a lot. Whip out the phone, call in front of the student and the class. A 15 second conversation which goes something like this. “Hello Mr Brown. This is Bob Brandis. I’m sorry to interrupt but I just rang to say Bill is having a fabulous day and trying his hardest at his school work. Thanks for your support at home. Have a nice day!”
Honestly, every mouth drops in the class and Mr Brown is probably receiving CPR at work. I have even left the same message on answering machines. You can imagine the student rushing to get home and wait for Mum/Dad to arrive so they can get the message.
The impact on the class is immediate.