If you want to cut out the largest circle in a square cardboard with a side length of 10 cm, what is the remaining area?
要在一个边长为10厘米的正方形纸板里剪出一个最大的圆，剩下的面积是多少．
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">100 - 78.5</gadget>
<output>21.5</output>

<result>21.5</result>