There are two circles, big and small. The circumference of the big circle is 25.12 meters, and the diameter of the small circle is (1/2) the diameter of the big circle. How many square meters is the area of the small circle?
有大小两个圆，大圆周长是25.12米，小圆的直径是大圆直径的(1/2)，小圆面积是多少平方米？
<gadget id="calculator">25.12 / 3.14</gadget>
<output>8</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">8 * (1/2)</gadget>
<output>4</output>

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

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>