In a cuboid container with an inner length of 30 cm, a width of 15 cm, and a height of 12 cm, there is water at a height of 5 cm. After a piece of iron is placed inside and is completely submerged, the water level rises to 9 cm. What is the volume of the iron block placed in the water?
在一个内部长30厘米，宽15厘米，高12厘米的长方体容器中有5厘米高的水，往里放一块铁块完全浸没后，水面升高到9厘米处．放入水中的铁块的体积是多少？
<gadget id="calculator">9 - 5</gadget>
<output>4</output>

<gadget id="calculator">30 * 15 * 4</gadget>
<output>1_800</output>

<result>1_800</result>