Stone can also be made into special paper through special process, which is the advocated "low carbon economy". A production process factory introduced this technology, planned to complete 5 million tons in the first half of the year, and actually completed (1/5) every month. In this way, how many tons can be overfulfilled in half a year?
石头也能经过特殊的工艺制造成特殊的纸，这就是所提倡的"低碳经济"．某生产工艺厂引进该技术，上半年计划完成500万吨，实际每月完成(1/5)，照这样，半年可以超额完成多少万吨？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">500 * (1/5) * 6</gadget>
<output>600</output>

<gadget id="calculator">600 - 500</gadget>
<output>100</output>

<result>100</result>