A Word Sum Puzzle (also known as WSP) is a word game that requires simple mathematical operations, and vocabulary skills to be solved. The solution is always a single word that contains four or more letters.
A WSP has a clue and two or more hints, where the clue is a meaning for the solution (a single word) and each hint gives the sum of the numbers assigned to the first two, four, etc. letters of the solution[1]. In an English WSP, the numbers assigned to the letters are as the same of their orders in English alphabet:
A, a = 1 B, b = 2 C, c = 3 D, d = 4 ... Z, z = 26
Example
editA curved part of a path:
_ _ (7)
_ _ _ _ (25)
The first line of the puzzle presents a clue; in this puzzle, "A curved part of a path" is the puzzle's clue. The other lines of the puzzle are its hints. This puzzle has two hints:
FIRST HINT _ _ (7)
This hint indicates that the first two letters of the answer make a sum of 7. Hence, the first two letters can be: A & F (or F & A), B & E, C & D or D & C
SECOND HINT _ _ _ _ (25)
This hint indicates that the first four letters of the answer make a sum of 25. But based on the first hint, it is already known that the first two letters made a 7, therefore the third and fourth letters make a sum of 18. So they can be: A& Q, B & P, C & O, D & N, E & M, ... I & I
To solve the puzzle, the player should find which two pairs of letters obtained from these hints can make a word that means “A curved part of a path”.
A & F + A & Q – (NO) A & F + B & P – (NO) ... B & E + D & N (YES) The solution for this example is "bend".
References
edit1. G.R. Worder, Word Sum Puzzles, 2010