A square with a side length of 250 meters, how many kilometers will it take to walk 4 times around it?
一块正方形地，边长是250米，绕它四周走4圈，一共要走多少千米．
<gadget id="calculator">4 / 1_000</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">250 * 4 * (1/250)</gadget>
<output>4</output>

<result>4</result>