Alphametics, first published in their modern form by H. E. Dudeney in 1924, are a subset of word/math puzzles known as cryptarithmetic puzzles presented in the form of a sum. A solution is the corresponding integers which should replace the letters to make the sum true.

Consider Dudeney's puzzle:

```                SEND
+MORE
-----
MONEY
```
Solution:
```                9567    (D=7, E=5, M=1, N=6, O=0, R=8, S=9, Y=2)
+1085
-----
10652
```
These puzzles must conform to the following rules:
• The leftmost letter can not be zero in any word (in the above example, S and M are not equal to zero).
• There must be a one-to-one mapping between letters and digits.

The most elegant alphametics have only one solution. More impressive alphametics still are those which are doubly-true -- consider this example, provided by Michael Keith on his web site:

```                SEVEN
SEVEN
+  SIX
-----
TWENTY
```
Check out Michael Keith's page for more: http://members.aol.com/s6sj7gt/

Log in or register to write something here or to contact authors.