三亿用英语怎么说?

300 million or 0.3 billion
二楼是对的。解释哈，million是表示百万，billion表示10亿。希望对你有所帮助.

补充：as well as
“也”“和”的意思，跟and意思很象，但是用法有点不同。
主要表现在谓语单复的问题。
A and B做主语时，谓语一般是复数，而且a和b同为主语。
eg:He and his cusotmer are beyund trust.
他与他的客户互不信任。

As well as
He as well as his cusotmer is beyoud trust.
他与他的客户互不信任。

意思没有变。建议。如果是口语话，用and较通俗易懂。如果是书面表达或者是考试写作文时则用as well as,比较地道，是加分点！

300 million

300 million

as well as
conj.（连接词）
And in addition:
既…又：
courageous as well as strong.
既健康又勇敢
prep.（介词）
In addition to:
都：
The editors as well as the proofreaders are working overtime.
编辑和校对者都在加班工作

300 million or 0.3 billion

300 million