Zhang Qiang deposits the 800 yuan lucky money he got this year into the bank for 3 years, with an annual interest rate of 2.70%. How much after-tax interest will Xiaoqiang get when it matures. (The interest on deposits is taxed at a rate of 20%)
张强把今年得到的800元压岁钱存入银行，存整存整取3年，年利率是2.70%，到期时小强可得到税后利息多少元．(存款的利息要按20%的税率纳税)
<gadget id="calculator">2.7 / 100</gadget>
<output>0.027</output>

<gadget id="calculator">800 * 0.027 * 3</gadget>
<output>64.8</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">64.8 * (4/5)</gadget>
<output>51.84</output>

<result>51.84</result>