Calcudoku (Mathdoku) Puzzle
Place 1 to n once in every row and column so each cage hits its target. Pick a size, tap a cell, enter digits with the keypad or your keyboard, and press Check whenever you like.
Select a cell, then tap a digit from 1 to 6.
How to play Calcudoku
One of each digit
On a 6×6 grid, every row and every column holds the digits 1 to 6 exactly once. A 4×4 uses 1 to 4, and a 7×7 uses 1 to 7.
Hit every cage
A cage is a group of cells with a thick border. Its digits must make the target in its corner with the operator shown, such as 12× or 3−.
Select and type
Tap a cell, then tap a digit on the keypad or type it. Turn on Notes to pencil in the digits a cell could still be.
Calcudoku is a number puzzle that mixes a Latin square with a little arithmetic. It is also called Mathdoku. Every row and column holds each digit once, like a small sudoku without boxes, and heavy-bordered cages tell you what their digits add, subtract, multiply or divide to. You can play grids from 4×4 up to 7×7, and every puzzle here has exactly one solution that you can reach by logic, with no guessing.
Rules
An n×n grid takes the digits 1 to n. A 4×4 uses 1 to 4, a 6×6 uses 1 to 6, and so on. Each digit appears exactly once in every row and exactly once in every column.
The grid is divided into cages, outlined with thick lines. The corner of each cage shows a target and an operator.
In a + cage the digits add up to the target, and in a × cage they multiply to it. A − cage and a ÷ cage always have two cells: the larger digit minus the smaller one, or the larger divided by the smaller, gives the target. So on a 6×6, 3− is 1 and 4, 2 and 5, or 3 and 6, in either order.
A digit may repeat inside a cage, as long as the repeats are in different rows and different columns. The row and column rule still holds.
A cage of one cell shows just a digit. That digit is given, and it starts filled in.
The puzzle is solved when every row and column has each digit once and every cage hits its target.
Controls
Tap a cell to select it. Its row and column are tinted, and any cell with the same digit is shaded a little darker. Tap a digit on the keypad under the board, or type it. Erase, Backspace, Delete or 0 clears the cell, and the arrow keys move around the grid. Given digits can be selected but not changed.
Notes are small pencil marks for the digits a cell could still be. Turn on Notes with the button or the N key, then each digit you tap or type switches that mark on or off. Shift with a digit adds or removes a note without turning Notes on. When you place a digit, that digit’s notes disappear from the rest of its row and column, in the same undo step.
A repeated digit in a row or column, a digit that no filling of its cage can use, and a full cage that misses its target are marked red as soon as they appear. A full cage that hits its target turns soft teal. The line under the keypad names the selected cage and how many of its cells are still open. Press Hint for a digit the rules already force, with the idea behind it. Press Check when you want the board scored against the rules. Undo and Redo step through your moves, and Reset clears the grid back to the givens.
Beginner tips
Start with cages that can only be made one way. In two cells on a 6×6, 3+ is always 1 and 2, 11+ is always 5 and 6, 30× is 5 and 6, and 5− is 1 and 6. The order then comes from the row and column.
Look at big products and small sums. A × target with a factor of 5 needs a 5 in the cage, and a ÷ target of 3 on a 6×6 can only be 1 and 3 or 2 and 6.
Each row of an n×n grid adds up to the same total: 10 on a 4×4, 15 on a 5×5, 21 on a 6×6 and 28 on a 7×7. When + cages cover all of a row but one cell, subtract their targets from that total to find the missing digit. Easy grids fall to single fillings and last places, and harder grids ask you to compare the fillings of a cage with what its row and column already hold.