Something interesting I learned yesterday:
It is not discouraged in (at least one) UK-system international schools in China to have Y12s do Y13 Olympiads. I've met two doing A Levels that got a Gold and Silver lmao.
It's like if you make a very gross generalisation:
Year 9: I wanna start preparing for GCSEs and University
UK: Oh, you're in Year 9! Go play and do whatever you want and I won't even care what you decide to explore on the internet. [Proceeds to neglect and kill child's desires and ambitions]
Singapore: Do it! Here're a bunch of books for you to read. Also I recommend you to attend a few overpriced tuition that most wealthy Chinese parents will happily pay double for [proceeds to make child myopic and stressed]
China: Huh, only now? My son has already learned 1500 characters before he started primary school, and has attended illegal private tuition to boost his grades for 9 years [child proceeds to be outperformed by entire cohort that has been studying more advanced material since primary]