Master Wang processes a batch of parts. On the first day, he processed (2/9) of this batch of parts. If 150 more parts are processed, the ratio of processed parts to remaining parts is 1:1. How many parts are there in this batch?
王师傅加工一批零件，第一天加工了这批零件的(2/9)，如果再加工150个，则已加工的与剩下的比是1：1，这批零件共有多少个？
<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(1/2) - (2/9)</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">150 / (5/18)</gadget>
<output>540</output>

<result>540</result>