Cross Sums (~Weekly) by X-Sums 98! - Version 1.0.0.8 Solve More-or-Less Weekly, computer-generated Cross Sums Puzzles with the X-Sums 98 Viewer! The weekly puzzles may be Challengers, but the viewer also has 12, built-in puzzles of varying difficulty. Cross Sums puzzles are similar to crossword puzzles except that numbers are used instead of words; digits instead of letters. New, ZOOM feature!!!