DS got a 6C in his maths at the end of year 6 and has just started in secondary in year 7. I've been looking at his maths homework. This week it was to revise the 2, 5 and 10 times tables. He's also told me that he's finishing the work early in class and finding it very easy. I phoned up the school and asked the head of learning for year 7 and asked how they set for maths, and whether ds has ended up in a lower set because of a poor performance in the banding tests that were done for admissions purposes. He said that the higher sets had children in them who had level 5's across the board. DS's SATS were 6 (maths) 5 (reading) and 4a (writing). So he's been put in a lower set for maths. 
Maths is far and away his strongest subject. I appreciate that a 6C isn't spectacular, but he did that completely on his own with no maths practice (not more than half an hour a week of homework which he did without help from DH or I) and no tutoring. He would routinely get 120/120 in every single times table test with no practice at all. I feel a bit gutted that his weakest subject (writing) is determining the level of his strongest subject (maths). I'm now worrying that he's also been set in this way for science.
Has anyone come across this way of setting for maths before? What do you think?
Now off to start another thread about his weak writing!