Zhang Min ran 4 laps around the 400-meter track and field, and the difference was exactly 2 kilometers.
张敏绕着400米的田径场跑4圈，还差多少正好是2千米．
<gadget id="calculator">2 * 1_000</gadget>
<output>2_000</output>

<gadget id="calculator">400 * 4</gadget>
<output>1_600</output>

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

<result>400</result>