To make a cylindrical water tank (without a cover), the height is 12 meters, and the diameter of the bottom surface is 6 meters. If 2 kilograms of aluminum skin is used per square meter, how many kilograms of aluminum skin do you need?
要做一个圆柱形水箱(无盖)，高是12米，底面直径是6米，如果每平方米要用铝皮2千克，需用铝皮多少千克？
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<gadget id="calculator">3.14 * 6 * 12</gadget>
<output>226.08</output>

<gadget id="calculator">28.26 + 226.08</gadget>
<output>254.34</output>

<gadget id="calculator">254.34 * 2</gadget>
<output>508.68</output>

<result>508.68</result>