Chen Xing went to Xinhua Bookstore and bought two books: a copy of "Manga King" for 5.4 yuan, and a copy of "Manga King" for 4.2 yuan. How much did Chen Xing spend on these two books? How many.
陈星到新华书店买了两本书：一本《漫画大王》5.4元，一本《漫画大王》4.2元．买这两本书陈星用了多少钱？多少．
<gadget id="calculator">5.4 + 4.2</gadget>
<output>9.6</output>

<result>9.6</result>