The master and the apprentice process a batch of parts together. The master processed (11/20) of this batch of parts, and the apprentice processed (9/20) of this batch of parts, 80 less than the master. How many parts are there in this batch?
师徒两人共同加工一批零件，师傅加工了这批零件的(11/20)，徒弟加工了这批零件的(9/20)，比师傅少加工80个．这批零件有多少个？
<gadget id="calculator">11 / 20</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(11/20) - (9/20)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">80 / (1/10)</gadget>
<output>800</output>

<result>800</result>