Cross Sums and Kakuro are the same puzzle
If you learned this puzzle from American magazines, you probably know it as Cross Sums — the name Dell Magazines used when it introduced the puzzle in 1966. Cross Sums, Cross Addition, and Kakuro all describe the identical game: fill white cells with digits 1–9 so each run matches its clue sum, never repeating a digit within a run.
The Kakuro name arrived by way of Japan, where the imported puzzle was called kasan kurosu ('addition cross') and later contracted to Kakuro. When Japanese-branded puzzles boomed internationally in the mid-2000s, that name traveled back and became the common one online — but decades of Dell solvers still search for Cross Sums, and they end up at the very same grid.
Playing Cross Sums today
Every board on this site is a Cross Sums puzzle in the classic sense: a symmetric black-and-white grid, slash clues, and a single logical solution. There is a shared daily board each midnight Eastern, an archive of every past daily, and an unlimited library across five sizes graded [easy](/puzzles/difficulty/easy) to [hard](/puzzles/difficulty/hard).
The solving aids are modern — tap a clue for its live digit-combination list, pencil-mark candidates on touch or keyboard — but nothing about the puzzle itself has changed since 1966. If you solved Cross Sums on paper, the [combination tables](/combinations) will read like an old friend.