Master Zhou has to process 300 parts. He processed it on the first day (3/20), and the quantity processed on the second day was less than that on the first day (1/5). How many parts did Master Zhou process in two days?
周师傅要加工300个零件，他第一天加工了(3/20)，第二天加工的数量比第一天少(1/5)，周师傅两天共加工零件多少个？
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">300 * (3/20)</gadget>
<output>45</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">45 * (4/5)</gadget>
<output>36</output>

<gadget id="calculator">45 + 36</gadget>
<output>81</output>

<result>81</result>