If the perimeter of a square increases by 20%, how much does the area increase?
正方形周长增加20%，面积增加多少．
<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">(6/5) ** 2</gadget>
<output>36/25 = around 1.44</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

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

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