twenty

我给了服务员一张二十块的，他立刻眉开眼笑。

你现在在哪儿，伙计？ (This translation uses "你现在在哪儿？" which means "Where are you now?" This is a natural and common way to ask someone's location in Chinese, and implicitly conveys the meaning of being somewhere in the general area.)

国王的二十人队在城堡防御战中英勇作战。

我弟弟今年二十岁了。