A cylindrical grain hoard has a bottom diameter of 6 meters and contains 2.5 meters of wheat. If each cubic meter of wheat weighs 0.8 tons, how many tons of wheat does this grain hoard contain? (Estimate the number first, then calculate)
一个圆柱形粮囤，底面直径6米，装有2.5米高的小麦，如果每立方米小麦重0.8吨，这个粮囤有小麦多少吨？(先估计得数，再计算)
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

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

<gadget id="calculator">3.14 * 9 * 2.5 * 0.8</gadget>
<output>56.52</output>

<result>56.52</result>