Kakuro and Calcudoku for iPhone.
Two classic number puzzles in one calm app. Fill the grid so every sum adds up. Play a new puzzle of each type every day.
Free: one daily Kakuro, one daily Calcudoku and unlimited Easy puzzles. A one-time purchase of $6.99 (US price) unlocks Medium, Hard, Expert, the daily archive and unlimited hints (3 free hints a day). No ads. No account. No subscription.
Kakuro
Put the digits 1 to 9 in the white cells. Each run of cells adds up to the clue beside it. A run never uses the same digit twice.
Calcudoku
Each row and column holds each number once. Each outlined cage must reach its target number with the math sign shown: add, subtract, multiply or divide.
Screenshots
A daily puzzle, free
A new Kakuro and a new Calcudoku every day. Everyone gets the same puzzles. Keep your streak going.
Four levels
Easy, Medium, Hard and Expert, in several grid sizes. Every puzzle has exactly one solution.
Tools that help
Pencil marks, undo and redo, a timer, and mistake marks you can turn off. Leave a puzzle and pick it up later.
Plays anywhere
Works offline, with no internet needed. Supports dark mode and VoiceOver. Menus follow your text size.
Fair price
No ads and no subscription. Pay once to unlock everything, or keep playing free.
Private
No account. Anonymous usage data only, and you can turn it off. Read the privacy policy.
Learn the puzzles
- How to play Kakuro
The rules, and a small puzzle solved step by step.
- How to solve Kakuro
Six methods from easy to hard, with diagrams.
- Kakuro combinations chart
All 502 combinations by sum and cell count.
- How to play Calcudoku
The rules of Calcudoku (Mathdoku), and a 4 × 4 example.
- Best Kakuro apps for iPhone
Seven apps compared, with facts from the App Store.
Questions
What is Cross Sums?
Cross Sums is an iPhone app with two classic number puzzles: Kakuro and Calcudoku. You get a new puzzle of each type every day.
Who is Cross Sums for?
It is for people who like Sudoku or crosswords and want a new logic puzzle. Beginners get a 1-minute tutorial and Easy puzzles. Experienced players get Hard and Expert puzzles.
What is Kakuro?
Kakuro, also called cross sums, is a crossword with numbers. Put the digits 1 to 9 in the white cells so that each run adds up to its clue. A run never uses the same digit twice.
What is Calcudoku?
Calcudoku, also called Mathdoku, is a math grid puzzle. Each row and column holds each number once. Each outlined cage must reach its target with the math sign shown.
Is Cross Sums free?
Yes. The daily Kakuro, the daily Calcudoku and unlimited Easy puzzles are free, with 3 hints a day. A one-time purchase of $6.99 (US price) unlocks Medium, Hard, Expert, the daily archive and unlimited hints.
Does Cross Sums have ads or need an account?
No. There are no ads, no account and no subscription.
Does it work offline?
Yes. Every puzzle works with no internet. You need a connection only to buy or restore the unlock.
What do I need to play?
An iPhone with iOS 17 or later.