How to count in Chinese

not 二十万=20万 is 200,000.
In China some said if it is more than 20, 200 for example they use “两” instead of "二“ so 两百。but it also not wrong to say 二百。it depends on which province you are in. just 入乡随俗.
so both 两万 and 二万 are correct or maybe 贰万 (er wan) as 二万？

only 万 means ten thousand here, so:
10,000=一万
20,000=二万 、两万
200,000= 二十万

use both 两万 and 二万

两万是对的