A cylindrical wooden block with a cross-sectional diameter of 40cm and a length of 30dm is processed into a square with a side length of 20cm and as large as possible. How many cubic decimeters of wood will be sawed off?
将一根横截面直径为40cm，长30dm的圆柱形木块，加工成边长为20cm的正方形并且尽可能大的方木．要锯掉多少立方分米木料？
<gadget id="calculator">40 / 20</gadget>
<output>2</output>

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

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

<gadget id="calculator">3.14 * 4 * 30</gadget>
<output>376.8</output>

<gadget id="calculator">2 * 2 * 30</gadget>
<output>120</output>

<gadget id="calculator">376.8 - 120</gadget>
<output>256.8</output>

<result>256.8</result>