cuboid container, the bottom surface is 4 decimeters long and 2.5 decimeters wide, and the water level rises by 0.4 decimeters after a stone is put in. What is the volume of this stone?
一个长方体容器，底面长4分米，宽2.5分米，放入一块石头后水面升高了0.4分米，这块石头的体积是多少？
<gadget id="calculator">4 * 2.5 * 0.4</gadget>
<output>4</output>

<result>4</result>