There are 2.5L of eye drops, if each 2ml is filled in a small bottle, how many bottles can be filled in total.
有眼药水2.5L，若每2ml装一小瓶，共可以装多少瓶．
<gadget id="calculator">2.5 * 1_000</gadget>
<output>2_500</output>

<gadget id="calculator">2_500 / 2</gadget>
<output>1_250</output>

<result>1_250</result>