rectangular fiberglass, measured from the inside, is 5 decimeters long and 3 decimeters wide. There is now 1.5 decimeters of water in the FRP. When a small stone is placed in the water, the depth of the water is 2 decimeters. What is the volume of the small stone in cubic centimeters?
一个长方形玻璃钢，从里面量，长5分米，宽3分米．玻璃钢里面现盛有1.5分米深的水．当把一块小石头放入在水中时，水深度为2分米．小石头的体积是多少立方厘米．
<gadget id="calculator">2 - 1.5</gadget>
<output>0.5</output>

<gadget id="calculator">5 * 3 * 0.5 * 1_000</gadget>
<output>7_500</output>

<result>7_500</result>