Fathom

It is late, the room is quiet, and one small grid is asking to be solved. That is where Fathom lives. Fathom is a KenKen puzzle — a Latin square wrapped in arithmetic. Fill every row and column with the numbers 1 to N and never repeat one. Then look at the bold cages: each shows a target and one operation, and the numbers you place inside must combine to hit it. A cage marked 12× wants its cells to multiply to twelve; a cage marked 3− wants a difference of three.

features
Sixty puzzles across four grid sizes
Easy 4×4 up to Expert 7×7
Add, subtract, multiply and divide cages
Pencil marks for the candidates you are weighing
A hint for when a grid stops making sense
Four scene themes and four board surfaces

Every puzzle has a single answer, and you can always reach it by reasoning alone — nothing here rewards a lucky guess. Tap a cell, choose a number, and watch its row and column light up so you can see what still fits. When two ideas compete, drop in pencil marks and come back to them later. Clear a grid with no mistakes and no hints and all three stars are yours. The grids start gentle and grow, so there is room to warm up before the Expert sizes bite.

Made for anyone who likes to sit with a number puzzle and think it through.