Sum Grid
Fill the grid to hit every target sum.
Sum Grid is a number-logic puzzle for anyone who likes their brain teasers with a bit of arithmetic. Every row and column shows a target sum along the edge — your job is to fill the grid so every one of them checks out.
Get it on
Google Play
Coming soon
App Store
How to play Sum Grid
Every row and column shows a target sum along the edge. Tap an empty cell, then tap a digit 1-9 to fill it.
No digit repeats within the same row or column — similar to a Latin square, but constrained by sums instead of a fixed digit set.
Fill every cell so each row and column adds up to exactly its target. Every generated puzzle is checked to have exactly one solution.
Example
A row target of 12 across 3 cells could be filled with 3, 4, 5 — as long as those same digits also work for the columns above them.
Difficulty
Tips & strategy
- Start with rows or columns that have the fewest empty cells — they're the most constrained and easiest to solve first.
- Use Hint to reveal a stuck cell without losing your streak, and Check to see how many cells currently conflict.
- Track which digits are already used in a row/column as you go — it narrows your options fast.
Sum Grid FAQ
Is Sum Grid the same as Kakuro?+
They're related but different: Kakuro (see Mini Kakuro) uses irregular black/white run shapes with a clue per run, while Sum Grid is a full rectangular grid with one target sum per whole row and column.
Can digits repeat in Sum Grid?+
No — every digit 1-9 can appear at most once within the same row or the same column, which is what makes the target sums solvable uniquely.
Does every Sum Grid puzzle have only one solution?+
Yes. Every puzzle is generated and then verified with a solver before it's shown to you, so there's always exactly one way to fill in the blanks correctly.
Is Sum Grid good for kids learning addition?+
It's a great lightweight way to practice mental addition and logical deduction together — Easy 4×4 boards are approachable for kids who are comfortable adding small numbers.