A cube tank with a side length of 2dm, pour 5L of water into the tank, then put a pebble into the water, the pebble is completely submerged in the water, then measure the depth of the water to be 1.5dm, what is the volume of the stone in cubic decimeters?
一个正方体水槽，棱长为2dm，向水槽中倒入5L水后，再把一个鹅卵石放入水中，鹅卵石完全浸入水中，这时量得水深1.5dm，石头的体积是多少立方分米？
<gadget id="calculator">2 * 2 * 1.5</gadget>
<output>6</output>

<gadget id="calculator">6 - 5</gadget>
<output>1</output>

<result>1</result>