Mr. Zhang buys 20,000 yuan of five-year treasury bonds, and the annual interest rate is 4.50%. After five years, how much interest will Mr. Zhang get?
张老师购买五年期的国库券20000元，年利率是4.50%，五年后，张老师可得利息多少元？
<gadget id="calculator">4.5 / 100</gadget>
<output>0.045</output>

<gadget id="calculator">20_000 * 0.045 * 5</gadget>
<output>4_500</output>

<result>4_500</result>