village plans to build a 140-meter-long embankment in one month (30 days). As a result, 35 meters were repaired in 5 days. According to this calculation, how many days can it be completed in advance?
某村计划一个月(30天)修筑一条长140米的堤坝．结果5天就修了35米，照这样计算，可以提前几天完成？
<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<result>10</result>