Y5 DS has to stay in bottom group maths because there?s no space left in the other groups. He knows all his timestables and division tables back to front since y4 while some of the children still struggling with 3Xs and 4Xs. The problem is that a lot of the time he finds maths lessons too easy. If he finishes the tasks too early he will be given extra work to do or play computer games instead. What should I do?