Zhang Ping's father borrowed 2,000 yuan from the bank with a term of one year and an annual interest rate of 4%. How much interest will Zhang Ping's father pay to the bank after the loan expires?
张平的爸爸向银行贷款2000元，贷期一年，年利率是4%，到期后张平的爸爸要向银行付利息多少元？
<gadget id="calculator">4 / 100</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">2_000 * (1/25) * 1</gadget>
<output>80</output>

<result>80</result>