If a square glass with a side length of 2m is cut into the largest circle, the area is reduced by how much.
把一块边长2m的正方形玻璃切割成一个最大的圆形，面积比原来减少了多少．
<gadget id="calculator">2 * 2</gadget>
<output>4</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">4 - 3.14</gadget>
<output>0.86</output>

<gadget id="calculator">0.86 / 4</gadget>
<output>0.215</output>

<result>0.215</result>