If the diameter of a circle increases from 2 cm to 3 cm, its area increases by how many square centimeters.
一个圆的直径从2厘米增加到3厘米，它的面积增加了多少平方厘米．
<gadget id="calculator">3 / 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">3.14 * (9/4)</gadget>
<output>7.065</output>

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

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

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">7.065 - 3.14</gadget>
<output>3.925</output>

<result>3.925</result>