The machinery factory processes a batch of parts. The original plan is to process 180 per hour, but the actual processing is 20 more per hour than the original plan, and the result is completed 5 hours earlier. How many parts are there in total?
机械厂加工一批零件，原计划每小时加工180个，实际每小时比原计划多加工20个，结果提前5小时完成．这批零件共多少个．
<gadget id="calculator">180 * 5</gadget>
<output>900</output>

<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">900 + 100</gadget>
<output>1_000</output>

<gadget id="calculator">20 - 180</gadget>
<output>-160</output>

<gadget id="calculator">180 + (-160)</gadget>
<output>20</output>

<gadget id="calculator">1_000 / 20</gadget>
<output>50</output>

<gadget id="calculator">180 * 50</gadget>
<output>9_000</output>

<result>9_000</result>