The school carried out reading activities and purchased 455 science books, 245 more than story books. How many books are there in total?
学校开展读好书活动，购买了科技书455本，比故事书多245本，两种书一共有多少本书？
<gadget id="calculator">455 - 245</gadget>
<output>210</output>

<gadget id="calculator">210 + 455</gadget>
<output>665</output>

<result>665</result>