large barrel of mineral water weighs 20L, and a small bottle of mineral water is 500ml. Excuse me: How many small bottles of mineral water are equal to the volume of a large bucket of mineral water.
一大桶矿泉水的体积重20L，一小瓶矿泉水500ml．请问：一大桶矿泉水的体积相当于多少小瓶矿泉水．
<gadget id="calculator">20 * 1_000</gadget>
<output>20_000</output>

<gadget id="calculator">20_000 / 500</gadget>
<output>40</output>

<result>40</result>