Xinhua Bookstore bought a batch of storybooks, 300 in total, and after selling some, there were 3 packs left, each with 25 books, how many were sold?
新华书店购进了一批故事书，共300本，卖出一些后，还剩3包，每包25本，卖出了多少本？
<gadget id="calculator">25 * 3</gadget>
<output>75</output>

<gadget id="calculator">300 - 75</gadget>
<output>225</output>

<result>225</result>