Master Zhang and Master Li jointly process 1000 parts. Master Zhang first made 220 pieces in 4 days, and Master Li finished the rest in 15 days. How many pieces does Master Li make every day?
张师傅与李师傅共同加工1000个零件．张师傅先做了4天，一共做了220个，剩下的由李师傅15天做完，李师傅每天做多少个？
<gadget id="calculator">1_000 - 220</gadget>
<output>780</output>

<gadget id="calculator">780 / 15</gadget>
<output>52</output>

<result>52</result>