In calcudoku every outlined cage has a target and an operation. Our generator builds each grid and the calcudoku solver checks that it has exactly one answer and that its step logic can finish it without guessing, so every puzzle here is fair.
Calcudoku rules
- Fill an n by n grid with the numbers 1 to n, once in each row and each column.
- Each cage shows a target and an operation. The numbers in the cage must reach the target with that operation: add them (+), multiply them (×), or for two-square cages take the difference (−) or the quotient (÷), larger number first.
- A number may repeat inside a cage as long as the copies are in different rows and columns.
- A cage of one square simply gives its number.
Tap a square and a number; Pencil writes candidates. When a cage is full and misses its target, or a number repeats in a line, its squares turn red.
Levels
Easy is 4 by 4, medium 6 by 6 and hard 7 by 7, all using the four operations. Every grid is solved by the solver's logic alone before you get it: one-square cages, the combinations a cage allows given its row and column, the only place left for a number in a line, and those checks repeated.
Tips
- Start with one-square cages and two-square cages whose target has only one pair: on a 6 by 6 grid, 11+ is always 5 and 6, and 30× is 5 and 6.
- Division and subtraction cages with large results are tight: 3÷ on a 6 by 6 grid is 1 and 3 or 2 and 6.
- Products are great for ruling numbers out: a cage of 7× on a 7 by 7 grid must contain 7 and 1.
- Every row adds up to the same total (n times n plus 1, halved). Use it when a row holds only whole cages and one loose square.
Hints and stats
Hint gives the next step with its arithmetic, for example which pairs fit a cage, and places the number. Check, Show mistakes, undo and redo work as in our other puzzles; best times and the daily streak are saved per level in your browser. Like the arithmetic? Kakuro uses sums in runs, and killer sudoku uses cage sums on a sudoku grid.
Solver tested . Found a problem? Tell us.
Questions
Is calcudoku the same as other math cage puzzles?
Calcudoku is a generic name for this kind of puzzle: a Latin square split into cages with arithmetic targets. Other names are used for branded versions of the same idea.
Can a number repeat in a cage?
Yes, if the repeated numbers are not in the same row or column. A three-square L-shaped cage of 12× on a 4 by 4 grid can hold 2, 3 and 2.
Which way do subtraction and division go?
Always larger number first, so the target is never negative or a fraction. A 2÷ cage holds two numbers where one is twice the other, in either square.
Will I ever need to guess?
No. Each grid is checked to be solvable by logic steps alone, with exactly one answer.