Two master workers, A and B, work together to process a batch of machine parts and complete the task in 20 days. It is known that A makes 3 more parts than B every day, and B asks for leave for 5 days in the middle, and the number of parts completed by B is exactly half of that of A. How many parts are there in total?
甲、乙两位工人师傅共同加工一批机器零件，20天完成了任务．已知甲每天比乙多做3个，而乙在中途请假5天，乙所完成的零件数恰好是甲的一半，则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">(2/3) / 20</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">(1/3) / 15</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">(1/30) - (1/45)</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">3 / (1/90)</gadget>
<output>270</output>

<result>270</result>