Xiaojun deposits 400 yuan of New Year's money in the bank for a period of two years. When it matures, what is the total amount of principal and interest? (At that time, the annual interest rate was 2.79%, and the interest tax was 5%)
小军将400元压岁钱存人银行，定期二年，到期时本金与利息一共多少元．(当时年利率为2.79%，利息税为5%)
<gadget id="calculator">400 + 21.2</gadget>
<output>421.2</output>

<result>421.2</result>