On the 400-meter lap track, Xiao Ming ran 2 and a half laps, how many kilometers did he run
在400米一圈的跑道上，小明共跑了2圈半，他跑了多少千米
<gadget id="calculator">2.5 / 1_000</gadget>
<output>0.0025</output>

<gadget id="calculator">400 * 0.0025</gadget>
<output>1</output>

<result>1</result>