右边数起：
一个逗号：thousand
两个逗号：million
三个逗号：billion
百位与十位间加个and
1,234；one thousand two hundred and thirty-four
4,567,809 four million five hundred and sixty-seven thousand eight hundred and nine
5,678,120,567 five billion six hundred and seventy-eight million one hundred and twenty thousand five hundred and sixty-seven