worker wants to process a batch of parts. (3/5) of these parts have been processed, and there are 120 left unprocessed. How many parts are there in total?
某工人要加工一批零件，已加工了这批零件的(3/5)，还剩下120个没加工，这批零件共几个？
<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>