Xiaodong plans to deposit 3,000 yuan of his own savings in the bank for a period of one year, and plans to donate the after-tax interest (interest tax is calculated at 20%) to "extremely poor students" in poor areas. If the annual interest rate is 2.25 % calculation, how much he can donate after the expiration.
小东计划把自己积蓄的3000元钱存入银行，存期一年，准备到期后把税后利息(利息税按20%计算)捐献给贫困地区的"特困生"，如果年利率按2.25%计算，到期后他可以捐出多少元．
<gadget id="calculator">2.25 / 100</gadget>
<output>0.0225</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">3_000 * 0.0225 * 1 * (4/5)</gadget>
<output>54</output>

<result>54</result>