The distance from Xiao Ming to the supermarket is 250 meters. He went back and forth twice a day, how many kilometers did he travel in total?
小明到超市的距离是250米，一天他往返了2次，共行了多少千米．
<gadget id="calculator">2 / 1_000</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">250 * 2 * (1/500)</gadget>
<output>1</output>

<result>1</result>