A cylindrical bucket has a bottom diameter and a height of 4 decimeters, and the water level in the bucket is 2 cm lower than the mouth of the bucket. How many kilograms of water does this bucket have? (1 kg per cubic decimeter of water)
一个圆柱形水桶，底面直径和高都是4分米，桶里的水面比桶口低2厘米，这桶水有多少千克？(每立方分米水重1千克)
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 - (1/5)</gadget>
<output>19/5 = around 3.8</output>

<gadget id="calculator">3.14 * 4 * (19/5) * 1</gadget>
<output>47.728</output>

<result>47.728</result>