The goldfish tank is 4 decimeters long and 4 decimeters wide, and only 2 decimeters of water is poured into it. After putting in a small rockery, the water level rises by 6 cm. What is the volume of the rockery?
金鱼缸长4分米、宽4分米，里面只注入2分米深的水．放入一座小假山后水面上升6厘米．假山的体积是多少？
<gadget id="calculator">6 / 10</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4 * 4 * (3/5)</gadget>
<output>48/5 = around 9.6</output>

<result>48/5 = around 9.6</result>