Xiaoqiang bought two books. "Fairy Tale" is 12.56 yuan, and "Up and Down Five Thousand Years" is 2.5 yuan cheaper than "Fairy Tale". How much does Xiaoqiang pay?
小强买了两本书．《童话故事》12.56元，《上下五千年》比《童话故事》便宜2.5元．小强应付多少元钱？
<gadget id="calculator">12.56 - 2.5</gadget>
<output>10.06</output>

<gadget id="calculator">10.06 + 12.56</gadget>
<output>22.62</output>

<result>22.62</result>