(sometimes we provide two download links because it may happen that the main server / link is overloaded or slow or non responding - the files are identical. Just choose one, save to the Desktop, double click to install)
This puzzle can be played by anyone who can add two numbers. Based on the crossword rules, but uses numbers instead of words. The sum of digits of the numbers is the clue. A logical blend of sudoku (the japanese number puzzle game) and the Crossword (popular puzzle of western world).
A great game for logic game buffs.
(
The number crossword game, where clues are replced by sum of digits.)

The number crossword game, where you fill the crossword grid with numbers based on addition logic. Anyone who can add two numbers can play.
In a language crosswords, often you are frustrated with a clue, the answer of which God only Knows. Unlike crossword, the Cross-Sum puzzles are always solveable by anyone who can add two numbers.
Cross-Sum is a nice mixture of sudoku (the japanese number puzzle game) and the Crossword (popular puzzle of western world).
The game is compact, and easily understandable. You are provided with 30 puzzles of varying sizes and difficulty levels. The game is a freeware, and if you like the game you can download more puzzle sets for free from Yoogi Games.
Cross software and sum cross software and number sum software and crossword number software