One lap around the playground runway is 200 meters, and how many meters are left after running 3 laps is 1 kilometer.
绕操场跑道一圈是200米，跑了3圈后还差多少米是1千米．
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">200 * 3</gadget>
<output>600</output>

<gadget id="calculator">1_000 - 600</gadget>
<output>400</output>

<result>400</result>