Corresponding training: Xiaoli put a stone in a cylindrical fish tank with a bottom diameter of 20cm (measured from the inside) (the stone is completely submerged in water), and the water surface rises from 30cm to 34cm. What is the volume of this stone?
对应训练：小立在一个底面直径是20cm(从里面量)的圆柱形鱼缸里放了一块石头(石头完全浸没在水中)，水面由30cm上升到34cm，这块石头的体积是多少？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">34 - 30</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 100 * 4</gadget>
<output>1_256</output>

<result>1_256</result>