If a cube of wood with a side length of 40 cm is processed into a largest cylinder, what is the utilization rate of this cube of wood?
将一个棱长40厘米的正方体木料加工成一个最大的圆柱体，这块正方体木料的利用率是多少．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 40</gadget>
<output>50_240</output>

<gadget id="calculator">40 * 40 * 40</gadget>
<output>64_000</output>

<gadget id="calculator">50_240 / 64_000</gadget>
<output>157/200 = around 0.785</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(157/200) * 1</gadget>
<output>157/200 = around 0.785</output>

<result>157/200 = around 0.785</result>