"几十"和"十几"的英文怎么说?

几十: dozens of, several dozen. 比如：I have dozens of stamps.

或者 I have several dozen stamps.

如果是几十年，用 decades.

十几：about a dozen, 多了说 almost twenty。

偶尔也有人用不严格的说法: ten something。

打车去那个博物馆要十几块, 可以说：cost you about 15 dollars.