It takes 8 days for the master and 10 days for the apprentice to process the same 520 parts. How many more parts does the master make per day on average than the apprentice?
加工同样的520个零件，师傅要8天，徒弟要10天，师傅比徒弟平均每天多做多少个零件？
<gadget id="calculator">520 / 8</gadget>
<output>65</output>

<gadget id="calculator">520 / 10</gadget>
<output>52</output>

<gadget id="calculator">65 - 52</gadget>
<output>13</output>

<result>13</result>