The school bought a batch of new books and lent 275 books to classmates, leaving 225 books left. There are 291 popular science books in this batch of new books, and the rest are story books. How many story books are there?
学校买来一批新书，借给同学275本，还剩225本．这批新书中有科普知识291本，其余的是故事书．故事书有多少本？
<gadget id="calculator">225 - 291</gadget>
<output>-66</output>

<gadget id="calculator">275 + (-66)</gadget>
<output>209</output>

<result>209</result>