Rose, I'd follow Turnoi's advice. However, if there are some hostilities in between you and the employer now, i'd be careful approaching him/her/them. If you aren't on a Z visa, leave after the payday, but if you are you have to consider negotiating. Then, one month pro notice with reasons and the manager's signature might do the job, although a "Letter of Release" is sometimes helpful...depending where you want to go after.

Again, this all is NORMAL and it has happened to me too, although my employer compromised on that paper work then. The unexpected age groups, classes or new students in class also happens regularly in other mainland schools. Some foreign teachers are rented out to other schools as well and I have not only seen that but experienced it. Renting often happens when some schools do not have a license and, yes, renting is not so legal on mainland. If renting out is your case, you may also put that in your resignation reasons then.

It's stunning that kids at early age learn suchawrong approach to education in this country.

Cheers and beers to our fine gigs on mainland