I went to school 20+ years ago in a school of 3000+ kids in the UK. There simply never were room changes for us. I don't get why you'd make the kids change rooms. Just set the timetable for the year, now the kids are going to be in those rooms at those times. Simple. Any changes, just make the teachers deal with it. In a system where the children outnumber the teachers ~30:1 and have smaller brains and smaller bodies this seems to make more sense to me.
As for cancelled lessons, I wish! That never happened. We had a substitute teacher every time. But the substitute came to the room we were already scheduled to be in.
The only reasons I can think for making the kids change is if there's a problem with the room itself or if the teachers are not interchangeable between rooms. But I would have thought teachers would find room changes easier now than back then, if anything (given the use of ubiquitous technology like projectors etc.).
As for cancelled lessons, I wish! That never happened. We had a substitute teacher every time. But the substitute came to the room we were already scheduled to be in.
The only reasons I can think for making the kids change is if there's a problem with the room itself or if the teachers are not interchangeable between rooms. But I would have thought teachers would find room changes easier now than back then, if anything (given the use of ubiquitous technology like projectors etc.).