If the radius of the base of the cylinder is doubled and the height is reduced to 1/2, then its volume will be reduced to the original.
圆柱的底面半径变为原来的2倍，高变为原来的(1/2)，则它的体积变为原来的多少．
<gadget id="calculator">2 / 1</gadget>
<output>2</output>

<result>2</result>