cylindrical bucket has an inner diameter of 40 cm and a height of 50 cm. How many liters of pure water can be filled in this bucket?
一个圆柱形水桶，它的内直径是40厘米，高50厘米，这个水桶大约装纯净水多少升？
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

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

<gadget id="calculator">50 / 1_000</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">3.14 * 400 * (1/20)</gadget>
<output>62.8</output>

<result>62.8</result>