Naughty bought a copy of "Fairy Tales" at the bookstore, and it cost 3.8 yuan. He bought another copy of "Mathematics World" and spent 11.5 yuan. How much did it cost to be naughty?
淘气在书店买了一本童话故事》，话了3.8元．他又买了一本《数学世界》，花了11.5元．淘气一共花了多少元？
<gadget id="calculator">3.8 + 11.5</gadget>
<output>15.3</output>

<result>15.3</result>