Dad bought a 5,000-yuan national bond with a term of two years. When it matures, he can get back the principal and interest of 5,873 yuan. What is the annual interest rate of this national bond?
爸爸买了5000元国债，定期两年，到期时可取回本金和利息共5873元，这种国债的年利率是多少？
<gadget id="calculator">5_873 - 5_000</gadget>
<output>873</output>

<gadget id="calculator">873 / 5_000 / 2</gadget>
<output>873/10_000 = around 0.0873</output>

<result>873/10_000 = around 0.0873</result>