One circle of the school playground is 400 meters, and two and a half circles are exactly how many kilometers.
学校操场一圈是400米，两圈半正好是多少千米．
<gadget id="calculator">400 * 2.5</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 / 1_000</gadget>
<output>1</output>

<result>1</result>