What is (1/5) of the area of a circle with a diameter of 4m?
直径是4m的圆，它的面积的(1/5)是多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3.14 * 4 * (1/5)</gadget>
<output>2.512</output>

<result>2.512</result>