The migrant workers team built a canal, planned to build 84 meters per day, and completed it in 35 days. The result was 140 meters per day. How many days ahead of schedule was it actually completed?
民工队修一条水渠，计划每天修84米，35天完成，结果每天修140米，实际提前几天完成？
<gadget id="calculator">35 / 140</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">84 * (1/4)</gadget>
<output>21</output>

<gadget id="calculator">35 - 21</gadget>
<output>14</output>

<result>14</result>