Master Li originally planned to process a batch of parts. He completed the original plan (4/7) on the first day, and processed 20 more on the second day. At this time, he had already done more than the original plan (2/7). How much did he plan to process? indivual?
李师傅原计划加工一批零件，第一天完成原计划的(4/7)，第二天又加工了20个，这时已做的超过原计划的(2/7)，原计划加工多少个？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">(2/7) - (4/7)</gadget>
<output>-2/7 = around -0.285714</output>

<gadget id="calculator">1 + (-2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">20 / (5/7)</gadget>
<output>28</output>

<result>28</result>