Chinese uses
两 (liǎng), not
二 (èr), before measure-style numerals like
万 (ten thousand) and
亿 (hundred million). So 'two hundred million' is
两亿, not
二亿. The same rule:
两万 (20,000),
两千 (2,000),
两百 (200) - but for plain digit-position counting like reading a phone number,
二 is used.
