DS1 in in Y9. I'd say his school h/w averages about 45 mins a night. This is a massive uplift on Y8 where I gather the HoY chipped the teachers about how little h/w they wer settingl! So I am pleased that they are finally knuckling down, though it's been hard getting DS (re-)focused as he is so out of the habit of doing regular h/w- so now, some 'single pieces' can take an hour and half for him to produce what to me looks like 15 or 20 minutes of focussed work!
I am a bit between a rock and hard place because I would like to put a timer on DS and shut his book once the 30 or 40 minutes is over, writing in his logbook that the work was all he'd managed to achieve in the allocated time, the idea being that he'd get the message as the school would for instance make him stay in to complete suboptimal, sparse homework.... BUT the reality is, this is the top academic performing comp in the county, and is very MC thus has loads of alpha, clever and committed DC on its roll. They have Y7s with maths A levels and so forth, so they don't need my DS to 'do well' to bring up any scores so the likely reaction, in reality, will be a shoulder shrug from the school, a demotion into a lower maths set and possibly being made to do double, not triple science, which I dare 'not risk' for him in these straitened times.
As for setting extra work- nah, that's boat's well and truly sailed by 13. I fine times tables andmental maths questions at him and DS2 (11) in the car, and I heavily encourage reading and so forth. Very occasionally I have persuaded DS1 to look in his KS3 Science book, for instance, to check the answer to something.
But I wish the school actually set an hour a night, every night, of proper, focussed, meaningful homework. I see my friend's DSs, 12 and 14, who are at a 'good' private and have been since age 7, and they have a far more disciplined attitude to work
because doing h/w is second nature to them.