A number Puzzle in which a group of arithmetical operations has some or all of its Digits replaced by letters or symbols, and where the original Digits must be found. In such a puzzle, each letter represents a unique digit.
See also Alphametic, Digimetic, Skeleton Division
References
Bogomolny, A. ``Cryptarithms.''
http://www.cut-the-knot.com/st_crypto.html.
Brooke, M. One Hundred & Fifty Puzzles in Crypt-Arithmetic. New York: Dover, 1963.
Kraitchik, M. ``Cryptarithmetic.'' §3.11 in Mathematical Recreations. New York: W. W. Norton, pp. 79-83, 1942.
Marks, R. W. The New Mathematics Dictionary and Handbook. New York: Bantam Books, 1964.