Dad deposits 2,500 yuan in the bank, deposits and withdraws for two years, and the annual interest rate is 4%. How much is the total interest after 2 years? If the interest tax is 20%, then the after-tax interest and the principal are more than one yuan?
爸爸将2500元存入银行，整存整取两年，年利率为4%，2年后利息共有多少元？若利息税为20%，那么税后利息和本金一共多元？
<gadget id="calculator">4 / 100</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2_500 * (1/25) * 2 * (4/5)</gadget>
<output>160</output>

<gadget id="calculator">2_500 + 160</gadget>
<output>2_660</output>

<result>2_660</result>