The Xiaoxiao family bought 4,000 yuan of national construction bonds. For three years, she plans to donate the interest after maturity to "Project Hope". If the annual interest rate is 4.5%, how much money can she donate after maturity?
笑笑家买了4000元国家建设债券．定期3年，她准备把到期后的利息捐给"希望工程"，如果按年利率4.5%计算，到期后她可捐多少钱？
<gadget id="calculator">4.5 / 100</gadget>
<output>0.045</output>

<gadget id="calculator">4_000 * 0.045 * 3</gadget>
<output>540</output>

<result>540</result>