A cylindrical grain hoard has a base radius of 3m measured from the inside and a height of 4m. If each cubic meter of wheat weighs about 650kg, how many tons of wheat can this grain store hold?
一个圆柱形粮囤，从里面量底面半径是3m，高4m．如果每立方米小麦约重650kg，这个粮囤能装多少吨小麦？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">4 / 1_000</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">650 * 3.14 * 9 * (1/250)</gadget>
<output>73.476</output>

<result>73.476</result>