先把数字从个位向前数,每三位数加一个分隔符号,也就是逗号,
例如：300,100,056读作：three hundred million one hundred thousand and fifty-six.
400,010,620,710 读作：four hundred billion ten million six hundred and twenty thousand seven hundred and ten.
2,500,030 读作：two million five hundred thousand and thirty.