Draw a circle on paper with a scale of 1:10. Its area is 12.56 square centimeters. What is the actual area of the circle in square decimeters?
把一个圆用1：10的比例尺画在纸上，它的面积是12.56平方厘米，这个圆的实际面积是多少平方分米．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2 / (1/10) / 10</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>