Math Grid (Calcudoku)
A number grid with arithmetic clues. No digit may repeat in a row or column, and the digits in each bold cage must combine to the target shown in its corner. This style of puzzle is also called Calcudoku.
How to play Math Grid
- On an n×n grid, place the digits 1 to n so that each appears once in every row and every column.
- Bold outlines mark cages. The label in a cage’s corner gives a target and an operation.
- +: the cage’s digits add up to the target. ×: they multiply to it. − and ÷ cages have two squares: the larger digit minus (or divided by) the smaller gives the target.
- A digit may repeat inside a cage as long as the copies are not in the same row or column. Single-square cages are filled in for you.
- Every puzzle is created by our generator and proven by a solver to have exactly one answer.
Controls
- Arrow keys: move 1–n: enter Shift + digit: note
- N: notes mode Backspace: erase Z: undo H: hint
Tips
- Start with ÷ and − cages and big × targets — they usually allow only one or two digit pairs.
- On a 6×6 grid, a “2÷” cage can only be 1-2, 2-4 or 3-6.
- Each row adds up to the same total (10 on 4×4, 15 on 5×5, 21 on 6×6, 28 on 7×7), which can pin down a missing digit.
- Select a square to see every digit combination its cage still allows; crossed-out ones clash with digits you placed.
FAQ
Which size should I start with?
4×4 teaches the rules in a minute or two. 5×5 and 6×6 are the sweet spot for most players, and 7×7 is a proper workout.
Why can a cage contain the same digit twice?
Only rows and columns forbid repeats. In an L-shaped cage, two squares that share neither a row nor a column may hold the same digit.