A bottle of shampoo is 400ml, how many liters are there in 5 bottles?
一种洗发水每瓶400毫升，5瓶一共有多少升．
<gadget id="calculator">400 * 5</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 / 1_000</gadget>
<output>2</output>

<result>2</result>