Deposit 4,000 yuan in the bank, deposit and withdraw for three years, if the annual interest rate is 3.96%, how much can you get back the principal and after-tax interest after maturity.
存入银行4000元，整存整取三年，若年利率是3.96%，到期后可取回本金和税后利息共多少元．
<gadget id="calculator">3.96 / 100</gadget>
<output>0.0396</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">4_000 * 0.0396 * 3 * (4/5)</gadget>
<output>380.16</output>

<gadget id="calculator">4_000 + 380.16</gadget>
<output>4_380.16</output>

<result>4_380.16</result>