New Year's Day is approaching, and the post office has launched a postcard, each set priced at 9 yuan. 56 sets were sold in one day on Saturday, and how many yuan were sold in total.
元旦将至，邮局推出一种明信片，每套售价9元．周六一天卖了56套，一共卖了多少元．
<gadget id="calculator">9 * 56</gadget>
<output>504</output>

<result>504</result>