A cuboid water tank is 10 decimeters long, 8 decimeters wide, and 4.5 decimeters deep. A stone is placed in it. At this time, the water level rises to 7 decimeters. What is the volume of the stone?
一个长方体水箱，长10分米，宽8分米，水深4.5分米，放入一块石头，这时水面上升到7分米，这块石头的体积是多少立方分米？
<gadget id="calculator">7 - 4.5</gadget>
<output>2.5</output>

<gadget id="calculator">10 * 8 * 2.5</gadget>
<output>200</output>

<result>200</result>