There are three brothers, the eldest is 20% older than the second, and the second is 20% older than the third. Question: By what percentage is the eldest brother older than the third child?
兄弟三人，老大的年龄比老二的年龄大20%，老二的年龄比老三的年龄大20%．问：老大比老三的年龄大百分之几？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1 * (6/5) * (6/5)</gadget>
<output>36/25 = around 1.44</output>

<gadget id="calculator">(36/25) - 1</gadget>
<output>11/25 = around 0.44</output>

<result>11/25 = around 0.44</result>