A cuboid water tank is 12 decimeters long, 7 decimeters wide and 5 decimeters deep. When a stone is placed in the tank and the water level rises to 6.5 decimeters, what is the volume of the stone?
一个长方体水箱，长12分米，宽7分米，水深5分米．当把一块石块放入水箱后，水位上升到6.5分米，这块石块的体积是多少？
<gadget id="calculator">6.5 - 5</gadget>
<output>1.5</output>

<gadget id="calculator">12 * 7 * 1.5</gadget>
<output>126</output>

<result>126</result>