27 small squares with equal edge lengths are put together to form a big square, and the surface area of the big cube is 972 square decimeters less than the sum of the surface areas of the original 27 small cubes. What is the volume of the large cube in cubic decimeters.
27个棱长相等的小正方块拼成一个大正方块，拼后的大正方体的表面积比原来27个小正方体的表面积总和少972平方分米．大正方体的体积是多少立方分米．
<gadget id="calculator">9 * 9 * 9</gadget>
<output>729</output>

<result>729</result>