When Uncle Wang writes a novel, he writes an average of 520 words a day. According to this calculation, how many words can he write in three weeks?
王叔叔写一本小说，平均每天写520字，照这样计算，三个星期可以写多少字？
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">520 * 21</gadget>
<output>10_920</output>

<result>10_920</result>