On a section of railway, it is planned to replace the old rails each 10 meters long with new rails each 12 meters long. If 600 old rails are removed, how many new rails need to be replaced? (answer in two ways)
在一段铁路上，计划用每根长12米的新钢轨替换每根长10米的就钢轨．拆下旧钢轨600根，需要换上新钢轨多少根？(用两种方法解答)
<gadget id="calculator">10 / 12</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">600 * (5/6)</gadget>
<output>500</output>

<result>500</result>