Master Zhang processes a batch of parts. The ratio of completed parts to unfinished parts is 2:7. If 280 more parts are processed, (2/3) of this batch of parts can be completed. How many parts are there in total?
张师傅加工一批零件，完成的个数与未完成的个数比是2：7，如果再加工280个，就可以完成这批零件的(2/3)，这批零件共有多少个？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">2 + 7</gadget>
<output>9</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(2/3) - (2/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">280 / (4/9)</gadget>
<output>630</output>

<result>630</result>