To build a railway, an average of 16 steel rails are used per 100 meters. To build a railway with a length of 42.5 kilometers, how many steel rails are used?
修一条铁路，平均每100米要用16根钢轨，要修42.5千米长的一条铁路，要用多少根钢轨？
<gadget id="calculator">16 / 100</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">(4/25) * 42.5 * 1_000</gadget>
<output>6_800</output>

<result>6_800</result>