A cylindrical grain hoard has a bottom circumference of 6.28 meters and a height of 2.5 meters. If each cubic meter can hold 500 kilograms of grain, how many tons of grain can this grain storage be filled with?
一个圆柱形粮囤，底面周长是6.28米，高是2.5米．如果每立方米可装粮食500千克，这个粮囤装满粮时能装粮多少吨？
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2.5</gadget>
<output>7.85</output>

<gadget id="calculator">0.5 * 7.85</gadget>
<output>3.925</output>

<result>3.925</result>