A story book is 27.8 yuan, which is 3.5 yuan more expensive than a science book. How much does it cost to buy a story book and a technology book altogether?
一本故事书27.8元，比一本科技书贵3.5元．买一本故事书和一本科技书一共需要多少元？
<gadget id="calculator">27.8 - 3.5</gadget>
<output>24.3</output>

<gadget id="calculator">24.3 + 27.8</gadget>
<output>52.1</output>

<result>52.1</result>