My son last year in the 6th grade had similar issues. He was bored “out of his mind” his words. I
Made a game out of each problem, but something he enjoys. It helped to bring it something he liked.
But getting him tested, at least for math, might be a good idea. What he is doing in class maybe not challenging enough for him. So what he is doing is his way of showing you, he is bored. My son was so bored they are putting him in Honors classes in 7th grade, that start next week. They expect him to be in the 8th grade before the end of this year.
Ask for testing and past test scores (that were done in lower grades) it might help. Always ask the teacher for tutoring can’t hurt.