A pencil is 8 cents. My brother bought 5 and paid the salesperson 5 yuan. How much should I get back?
一枝铅笔8角，哥哥买了5支，付给售货员5元钱，应找回多少元
<gadget id="calculator">0.8 * 5</gadget>
<output>4</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<result>1</result>