Master Zhang produced a batch of parts and produced 150 in 3 days, 30 less than 40% of the total number of parts. How many parts are there in this batch?
张师傅生产一批零件，3天生产了150个，比零件总数的40%少30个．这批零件共有多少个？
<gadget id="calculator">150 + 30</gadget>
<output>180</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">180 / (2/5)</gadget>
<output>450</output>

<result>450</result>