For a cylinder, the height is enlarged by 4 times, the radius of the bottom surface is reduced to the original (1/4), how much is the volume reduced to the original
一个圆柱，高扩大4倍，底面半径缩小到原来的(1/4)，体积是缩小到原来的多少
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">1 / 16</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">4 * (1/16)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>