If the circumference of the base of a cylinder is 31.4m and the height is less than the diameter of the base (2/5), what is its volume?
一个圆柱底面周长是31.4m，高比底面直径少(2/5)，它的体积是多少．
<gadget id="calculator">31.4 / 3.14</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">10 * (3/5)</gadget>
<output>6</output>

<gadget id="calculator">3.14 * 25 * 6</gadget>
<output>471</output>

<result>471</result>