1

There is only 1 cookie left in the jar, so we should share it.

用法提示：数字“1”作数词，表示数量“一”，修饰名词cookie。

If you add 1 to 9, the total is 10.

用法提示：数字“1”作为数词出现在加法算式中，表示数字一。

She picked 1 card from the deck and turned it over.

用法提示：数字“1”作数词，表示动作涉及的单位数量，修饰card。