How many liters are exactly 4 bottles of 250ml drinks?
4瓶250毫升的饮料正好是多少升．
<gadget id="calculator">250 * 4</gadget>
<output>1_000</output>

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

<result>1</result>