The radius of the small circle is 3dm, which is (1/4) of the radius of the large circle, and the area of the small circle is ((())/(())) of the large circle.
小圆半径是3dm，是大圆半径的(1/4)，小圆面积是大圆面积的((())/(()))．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * (1/4)</gadget>
<output>1/16 = around 0.0625</output>

<result>1/16 = around 0.0625</result>