At the beginning of 2006, Grandpa Wang deposited 100,000 yuan in the bank for one year at an annual interest rate of 2.25%. After the maturity date, the bank will deduct 20% of the interest tax. Grandpa Wang decided to re-deposit 100,000 yuan every year when it expires, and donate the interest to the Hope Project. How much does Grandpa Wang donate to Project Hope every year?
2006年初，王爷爷将10万元钱存入银行，定期一年，年利率是2.25%，到期后银行将扣去20%的利息税．王爷爷决定每年到期后再转存10万元，将利息捐给希望工程．王爷爷每年向希望工程捐款多少元？
<gadget id="calculator">10 * 10_000</gadget>
<output>100_000</output>

<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">100_000 * 0.0225 * 1 * (4/5)</gadget>
<output>1_800</output>

<result>1_800</result>