Huang Li bought two books at the bookstore, one for 9.8 yuan and the other for 23.4 yuan. If she paid 100 yuan, how much should she get back?
黄丽在书店买了两本书，一本9.8元，另一本23.4元，付100元，应找回多少元？
<gadget id="calculator">9.8 + 23.4</gadget>
<output>33.2</output>

<gadget id="calculator">100 - 33.2</gadget>
<output>66.8</output>

<result>66.8</result>