If the diameter of a large circle is exactly twice the diameter of the small circle, what is the area of the small circle equal to the area of the large circle?
一个大圆的直径正好是小圆直径的2倍，那么小圆的面积是大圆面积的多少
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>