The rules
- Standard sudoku rules: each number once per row, column and box.
- In addition, the numbers in each cage must add up to its corner sum.
- A number cannot repeat within the same cage.
- Tap a cell and type a number.
Getting started: A two-cell cage with a low or high sum has few options (3 = 1+2), and a single-cell cage is given outright.
Step by step
1Here is the puzzle. The fixed numbers are given.
- 6
2The cage sums narrow the options — 6 goes here.
- 68
3The cage sums narrow the options — 8 goes here.
- 684
4The cage sums narrow the options — 4 goes here.
4 more steps in this walkthrough — the full step-by-step solve is a Pluss feature. About Pluss →
Real puzzle no. 24 with its solution, shown step by step.
Common questions
Can I play right in the browser?
Yes. Pick a Sumdoku puzzle and solve it on screen — press “Check” to see if you are on track, and “Hint” if you get stuck. You can also print it.
Can I link to a specific puzzle?
Of course. Every puzzle has a number, and you can link straight to it: puzzles.flogvit.com/eng/sumdoku?nr=100. Replace 100 with the puzzle number — handy for challenging a friend with the very same puzzle.
Can I print the puzzles?
Yes. Each type has a print sheet for one or four puzzles with the answers on a separate page.
Are the puzzles free to use?
Yes, this is a free service. If you want to publish the puzzles elsewhere you must arrange it first — see copyright.