Lele spent 8.55 yuan to buy books, 3.2 yuan to buy pens, and paid 15 yuan to the salesperson. How much should I get back?
乐乐买书用去8.55元，买钢笔用去3.2元，付给售货员15元，应找回多少元？
<gadget id="calculator">15 - 8.55 - 3.2</gadget>
<output>3.25</output>

<result>3.25</result>