If the radius of the base of the cylinder is doubled and the height is doubled, how many times will the volume of the cylinder be doubled?
圆柱的底面半径扩大2倍，高也扩大2倍，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>8</output>

<result>8</result>