On a 100:1 drawing, the radius of a circular part is measured as 2 decimeters. What is the actual area of the circular part in square centimeters?
在一个100：1的图纸上，量得一个圆形零件的半径为2分米，这个圆形零件的实际面积是多少平方厘米．
<gadget id="calculator">100 / 1</gadget>
<output>100</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2 * (1/10)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) ** 2</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">3.14 * (1/25)</gadget>
<output>0.1256</output>

<result>0.1256</result>