si, or something- in shanghainese 4 and 10 are hard to differentiate
also note that the Japanese numbers 1-10, 100, 1000 10,000 100,000,000(hundred million) and (trillion)1,000,000,000,000 are originally from Chinese, (although there is another "Japanese" way to count 1-10)
The "Chinese" Japanese numbers:
- ichi
- ni
- san
- shi ("yon" is Japanese-only AFAIK)
- go
- roku
- shichi (again I tend to think of "nana" as a word that came from Japanese)
- hachi
- kyu/ku
- juu