Digging a cylindrical reservoir, known its bottom radius is 2 meters, pool depth is 2.5 meters, put cement on the bottom and inner wall of the pool, use 2.5 kilograms of cement per square meter, how many kilograms of cement is needed in total?
挖一个圆柱形的蓄水池，已知它的底面半径是2米，池深是2.5米，在水池的底面和内壁抹上水泥，每平方米用水泥2.5千克，共需水泥多少千克？
<gadget id="calculator">2 * 3.14 * 2 * 2.5</gadget>
<output>31.4</output>

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">31.4 + 12.56</gadget>
<output>43.96</output>

<gadget id="calculator">2.5 * 43.96</gadget>
<output>109.9</output>

<result>109.9</result>