Cube (algebra) however, easy to show that most numbers are not perfect cubes because "all" perfect cubes must have digital root 1, 8 or 9. That is their values modulo 9 may be only −1, 1 and 0. Moreover, the digital root of any number's cube can be determined by the remainder the number gives when divided by 3: Every positive integer can be written as the sum of nine (or fewer) positive cubes. This upper limit of nine cubes cannot be reduced because, for example, 23 cannot be written as the sum of fewer than nine positive cubes: The equation has
The Carnelian Cube The Carnelian Cube The Carnelian Cube is a fantasy novel by American writers L. Sprague de Camp and Fletcher Pratt. It was first published in hardcover by Gnome Press in 1948, and in paperback by Lancer Books in 1967. An E-book edition was published by Gollancz's SF Gateway imprint on September 29, 2011 as part of a general release of de Camp's works in electronic form. It has also been translated into Italian and German. The carnelian cube of the title is a small red "dream stone" confiscated by archaeologist Arthur Cleveland Finch from Tiridat Ariminian, one of the workers