Master Wang has processed a batch of parts. (3/5) of the total number of parts have been processed, and there are still 120 parts that have not been processed. How many parts are in this batch?
王师傅加工一批零件，已经加工了零件总数的(3/5)，还有120个没有加工，这批零件多少个？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">120 / (2/5)</gadget>
<output>300</output>

<result>300</result>