Xiao Ming goes to school and walks back and forth along the 500-meter road twice a day. How many kilometers does he have to walk in a day?
小明上学每天沿着500米的公路走两个来回，他一天要走多少千米．
<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>