The volume of a bucket of milk is 2 liters. My younger brother drank 200ml every day for 8 days, how many milliliters are left?
一桶牛奶的容量是2升．弟弟每天喝200毫升，喝了8天，还剩多少毫升？
<gadget id="calculator">2 * 1_000</gadget>
<output>2_000</output>

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

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

<result>400</result>