Worker Xiao Li has to process 420 parts. He has been processing 36 parts a day for 8 days. How many parts are left unprocessed?
工人小李要加工420个零件，已经加工了8天，每天加工36个，还剩多少个没有加工？
<gadget id="calculator">36 * 8</gadget>
<output>288</output>

<gadget id="calculator">420 - 288</gadget>
<output>132</output>

<result>132</result>