Zhang Ming has to walk 500 meters from home to school. He made two round trips that day. How many kilometers did he travel in total?
张明从家到学校要步行500米，这天他往返了2个来回，共行多少千米？
<gadget id="calculator">500 / 1_000</gadget>
<output>1/2 = around 0.5</output>

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

<result>2</result>