A batch of parts was jointly completed by Lao Zhang and Xiao Wang. It was originally planned that Lao Zhang made 30 more parts than Xiao Wang, but Xiao Wang actually made 20 fewer parts than planned. The total number of parts he made is 2 more than the total number (4/7) that Lao Zhang actually made, so how many parts are there in this batch?
有一批零件由老张和小王两人合作完成，原计划老张比小王多做30个，结果小王实际做的比计划做的少20个．他做的总数比老张实际做的总数的(4/7)还多2个，则这批零件共有多少个．
<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">30 + 40</gadget>
<output>70</output>

<gadget id="calculator">70 + 2</gadget>
<output>72</output>

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

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">72 / (3/7)</gadget>
<output>168</output>

<gadget id="calculator">168 * (4/7)</gadget>
<output>96</output>

<gadget id="calculator">96 + 2</gadget>
<output>98</output>

<gadget id="calculator">168 + 98</gadget>
<output>266</output>

<result>266</result>