To build a section of road, it is planned to build 50 meters per day, and it will be completed in 35 days. The actual repair is 20 meters more than the plan every day, and how many days ahead of the plan?
修一段公路，计划每天修50米，35天完成．实际每天比计划多修20米，比计划提前几天？
<gadget id="calculator">50 + 20</gadget>
<output>70</output>

<gadget id="calculator">35 / 70</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">50 * (1/2)</gadget>
<output>25</output>

<gadget id="calculator">35 - 25</gadget>
<output>10</output>

<result>10</result>