I explored the manipulatives idea with my son. He didn't want to bring anything to school because he felt it was weird. BUT he insisted I bring this idea up to the teacher. I felt like he was looking for understanding. He used a pencil grippy at school to occupy his hands and bounced it on his desk. The teacher allowed this and it was not a problem. I think this was explained to me as a way of diverting some brainpower so he could consentrate on tasks too simple.