Ding Ding bought three books at prices of 2.50 yuan, 3.40 yuan, and 3.75 yuan respectively. He paid the salesperson 10 yuan. How much should he get back?
丁丁买了三本书，价格分别为2.50元、3.40元、3.75元，他付给营业员10元，应找回多少元？
<gadget id="calculator">2.5 + 3.4 + 3.75</gadget>
<output>9.65</output>

<gadget id="calculator">10 - 9.65</gadget>
<output>0.35</output>

<result>0.35</result>