A cube glass container has an edge length of 3 decimeters and contains 2.2 decimeters of water inside. A stone is thrown into the glass container, and the water level rises by 2.5 decimeters. What is the volume of the stone?
一个正方体玻璃容器的棱长为3分米，里面装有2.2分米深的水，将一块石头投入玻璃容器中，水面上升2.5分米，求这块石头的体积？
<gadget id="calculator">2.5 - 2.2</gadget>
<output>0.3</output>

<gadget id="calculator">3 * 3 * 0.3</gadget>
<output>2.7</output>

<result>2.7</result>