The height of a cylinder is reduced to the original (1/2), the radius of the bottom surface is also reduced to the original (1/2), how much is its volume reduced to the original
一个圆柱的高缩小到原来的(1/2)，底面半径也缩小到原来的(1/2)，它的体积缩小到原来的多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) ** 2</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * (1/2)</gadget>
<output>1/8 = around 0.125</output>

<result>1/8 = around 0.125</result>