A pen is 4.5 yuan, and a ballpoint pen is 3.5 yuan. Xiao Ming buys a pen and a ballpoint pen and pays the salesperson 10 yuan. How much should I get back?
一支钢笔4.5元，一支圆珠笔3.5元，小明买一支钢笔和一支圆珠笔，付给售货员阿姨10元钱，应找回多少元钱？
<gadget id="calculator">4.5 + 3.5</gadget>
<output>8</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<result>2</result>