You do know that doesn't matter right? Each one of those kids will go back to where they live and IF they have caught something, which there is a far greater risk with no masks and no social distancing, then that whole household could get it. If they don't follow the rules it goes to another and another until it gets to someone vulnerable.
Kids can get virus, there is no evidence to say they CAN'T spread it to one another, the idea is through other methods you keep it out of the schools in the first place. If you fail to keep the R number down then schools turn into super spreading warehouses. Forget rule of 6 there are 90 odd kids in my daughters year, most of those have 2 parents and/or at least a few siblings, comfortably we can say that's at least 270 people I'm in contact by proxy without even counting grandparents, friends of these families, out of school clubs etc.
It will need a reset at somepoint and seeing it is half term anyway, 1 extra week isn't the biggest deal. This will give the circuit break the best chance of working.
