The master and the apprentice process a batch of parts, the apprentice first processes 310 pieces, and then the master and the apprentice work together. When the task is completed, the parts processed by the master are 140 fewer than the number of parts (4/7) in this batch. Knowing the efficiency of the master and the apprentice The ratio is 2:1, how many parts are there in this batch?
师徒两人加工一批零件，徒弟先加工310个，然后师傅、徒弟共同加工，完成任务时，师傅加工的零件比这批任务的(4/7)少140个，已知师徒效率的比是2：1，这批零件有多少个？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">140 * (1/2)</gadget>
<output>70</output>

<gadget id="calculator">310 - 140 - 70</gadget>
<output>100</output>

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

<gadget id="calculator">(4/7) * (1/2)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (4/7) - (2/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">100 / (1/7)</gadget>
<output>700</output>

<result>700</result>