Fill an N×N grid with numbers 1 to N. Like Sudoku, no number can repeat in any row or column. Additionally, groups of cells called 'cages' must satisfy arithmetic constraints.
How to Play
Tap an empty cell to select it.
Use the number keypad to enter a value.
Each cage displays a target number and operation symbol in its top-left corner (e.g., 6+, 2−, 12×, 3÷).
What Is a Cage?
A cage is a group of cells outlined by a bold dashed border. The top-left corner shows a target number and an operation symbol. The numbers in the cage must produce the target using that operation.
Operations
Addition (+): Can have multiple cells. The sum of all numbers must equal the target.
Subtraction (−): Always exactly 2 cells. The larger minus the smaller must equal the target.
Multiplication (×): Can have multiple cells. The product of all numbers must equal the target.
Division (÷): Always exactly 2 cells. The larger divided by the smaller must equal the target.
1+2=3 ✓
4−1=3 ✓
2×3=6 ✓
6÷2=3 ✓
Single-Cell Cages
A cage with only one cell shows just a number with no operation symbol. That number is the answer — fill it in right away as a sure clue!
Row / Column Rule
No number may appear more than once in the same row or column. (Same rule as Sudoku)
Completed Example
Here is a completed 3×3 grid filled with 1–3. Check how each cage's operation is satisfied.
Each row and column contains numbers 1 to N exactly once.
Numbers in a cage must produce the target using the specified operation.
Single-cell cages show the answer directly.
5+ cage: 2+3=5
1− cage: 2−1=1
2− cage: 3−1=2
6× cage: 1×2×3=6
Tip
Start with single-cell cages to lock in certain numbers first.
Check which numbers are already placed in a row or column to narrow candidates.
Use memo mode to note possible candidates in each cell and avoid mistakes.
For multiplication cages, factoring the target helps narrow down candidates quickly.
Math Sudoku simultaneously trains arithmetic fluency and logical reasoning. Tracking multiple constraints engages working memory under significant cognitive load.
Miyake et al. (2000) - Unity and diversity of executive functions
Reiter & Thornton (2013) - Using KenKen to Build Reasoning Skills, Mathematics Teacher