In order to meet the requirement of speeding up, a section of railway needs to replace the rails, and replace the old rails each 9 meters long with new rails each 12 meters long. This section of railway originally had 168 rails, how many new rails need to be replaced?
为适应提速要求，一段铁路需要更换铁轨，用每根12米长的新铁轨，换下每根长为9米的旧铁轨．这段铁路原来有168根铁轨，需换成多少根新铁轨？
<gadget id="calculator">9 / 12</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">168 * (3/4)</gadget>
<output>126</output>

<result>126</result>