Xiaoguang bought a sharpener with a price of 2.3 yuan, and paid 5 yuan, how much should he get back?
小光买了一个价格是2.3元的卷笔到刀，付了5元钱，应找回多少元．
<gadget id="calculator">5 - 2.3</gadget>
<output>2.7</output>

<result>2.7</result>