How much does the area of a circle increase when its diameter is increased by 50%.
一个圆的直径增加50%后，面积增加多少．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) ** 2</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">(9/4) - 1</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>