There are 870 copies of "Must-Read Ancient Poems" in Dazhong Bookstore, and each book is priced at 9 yuan. If they are all sold, how much can they sell for?
大众书店有《古诗必读》870本，每本售价9元，如果全部卖出，可以卖出多少元钱？
<gadget id="calculator">9 * 870</gadget>
<output>7_830</output>

<result>7_830</result>