If the length and width of a cuboid are increased by 3 times, the height remains the same, and the volume is increased by how many times than the original volume.
长方体的长与宽增加原来的3倍，高不变，体积比原来的增加多少倍．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>