Xiaoya bought a 2-liter bottle of ebony juice and poured 400 ml into the cup. How many ml is left?
小亚买了一瓶2升的乌梅汁，杯子里倒入400毫升，还剩多少毫升？
<gadget id="calculator">2 * 1_000</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 - 400</gadget>
<output>1_600</output>

<result>1_600</result>