How much revision should i do in the summer holidays?

Honestly, I don't think you should do ANY revision.
I'm in Yr10 going into Yr11 and I personally didn't do anything, although that's mainly because I don't enjoy studying and never do much of it anyway.

Putting that aside, if you really feel the need to study, don't do anything crazy. Watch a video on a topic from time to time or just flip through the textbook (if you have it).

It also depends on the subjects you're taking. I take History and there isn't much revision I could have done prior to starting the course. But for something like Math, you should try to do some basic questions so that you don't lose ur skill or ability or whatever u want to call it.

Also AMAZING predicted grades. I just wanted to add though that those are what you've been predicted for your actual GCSE examinations, so don't get too stressed if you don't get them on your first test, I mean it's a two year course for a reason.

I am in year 9 (going into year 10 in september) and i was just wondering how much to do. I have done all the work set during quarantine and my predicted grades are 2 7s, 3 9s and the rest 8s. How much should i do?