The iron and steel factory wants to produce a batch of steel, and plans to produce 600 tons per day, which will be completed in 20 days. The actual production is 800 tons per day, how many days earlier than the original plan?
钢铁厂要生产一批钢材，计划每天生产600吨，20天完成．实际每天生产800吨，实际比原计划提前几天完成？
<gadget id="calculator">20 / 800</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">600 * (1/40)</gadget>
<output>15</output>

<gadget id="calculator">20 - 15</gadget>
<output>5</output>

<result>5</result>