Xiaoqiang bought a stamp worth 80 cents, and he gave the salesperson 2 yuan, how much should he get back?
小强买一张8角钱的邮票，他给营业员2元钱，应找回多少钱？
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 - 8</gadget>
<output>12</output>

<result>12</result>