A math book is 6.5 yuan, which is 0.5 yuan cheaper than a Chinese book. How much are the two books in total?
一本数学书6.5元，比一本语文书便宜0.5元，两本书一共多少元？
<gadget id="calculator">6.5 + 0.5</gadget>
<output>7</output>

<gadget id="calculator">6.5 + 7</gadget>
<output>13.5</output>

<result>13.5</result>