A conical grain hoard has a base radius of 3 meters measured from the inside and a height of 4 meters. If each cubic meter of corn weighs about 750 kilograms, how many tons of corn can this grain store hold?
一个圆锥形粮囤，从里面量得底面半径是3米，高4米．如果每立方米玉米约重750千克，这个粮囤能装多少吨玉米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) ** 2</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">(1/3) * 3.14 * (9/4) * 4</gadget>
<output>9.42</output>

<gadget id="calculator">9.42 / 1_000</gadget>
<output>0.00942</output>

<gadget id="calculator">750 * 0.00942</gadget>
<output>7.065</output>

<result>7.065</result>