Use a piece of cylindrical wood with a circumference of 15.7 decimeters and a height of 4.2 decimeters to cut it into a largest cone. How many cubic decimeters is the volume of the wood to be cut off? (π takes 3.14)
用一块底面周长15.7分米，高4.2分米的圆柱形木块，加工削成一个最大的圆锥，要削掉的木块体积是多少立方分米？(π取3.14)
<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 ** 2</gadget>
<output>6.25</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3.14 * 6.25 * 4.2 * (2/3)</gadget>
<output>54.95</output>

<result>54.95</result>