To make a batch of parts, originally planned to make 150 parts per day, but actually made 30 more parts per day, and the task could be completed 6 days ahead of schedule. How many parts are there in this batch?
做一批零件，原计划每天做150个，实际每天多做30个，就能提前6天完成任务．这批零件有多少个？
<gadget id="calculator">1 / 150</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">150 + 30</gadget>
<output>180</output>

<gadget id="calculator">1 / 180</gadget>
<output>1/180 = around 0.005556</output>

<gadget id="calculator">(1/150) - (1/180)</gadget>
<output>1/900 = around 0.001111</output>

<gadget id="calculator">6 / (1/900)</gadget>
<output>5_400</output>

<result>5_400</result>