Zhang Ming deposits 4,000 yuan in the bank, the deposit period is six months, and the annual interest rate is 2.25%. How much after-tax interest can he get after maturity?
张明存人银行4000元，存期六个月，年利率是2.25%，到期后可以取得税后利息多少元．
<gadget id="calculator">2.25 / 100</gadget>
<output>0.0225</output>

<gadget id="calculator">4_000 * 0.0225 * 0.5</gadget>
<output>45</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">45 * (4/5)</gadget>
<output>36</output>

<result>36</result>