A cup can hold 0.2 liters of green tea water, a bottle of green tea water is 2 liters and 500 milliliters, how many milliliters are left after filling 8 cups.
一只杯子可以装0.2升绿茶水，一瓶绿茶水2升500毫升，装满8杯后还剩多少毫升．
<gadget id="calculator">0.2 * 1_000</gadget>
<output>200</output>

<gadget id="calculator">200 * 8</gadget>
<output>1_600</output>

<gadget id="calculator">2_500 - 1_600</gadget>
<output>900</output>

<result>900</result>