If the diameter of the base of a cylinder is doubled and the height is reduced to half, how many times will the volume of the cylinder be enlarged?
一个圆柱的底面直径扩大2倍，高缩小到原来的一半，圆柱的体积扩大多少倍
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<result>2</result>