Xiaoxiao's home is 500 meters away from school. He goes back and forth between home and school twice a day. How many kilometers does he travel every day?
笑笑家到学校有500米，他每天在家和学校之间往返2个来回，他每天行多少千米．
<gadget id="calculator">2 / 1_000</gadget>
<output>1/500 = around 0.002</output>

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

<result>2</result>