One of the most popular number puzzles. Sudoku puzzles don't require arithmetic to solve, instead requiring logical reasoning.

How to play

Deduce which number goes in each square following these rules: Only the numbers 1-9 can be used and cannot be repeated within the same line or 3x3 square (or 'nonet').
(Sudoku also supports puzzles with smaller grids, with 2x2 and 3x2 nonets. These only use the digits 1-4 and 1-6 respectively.)
You can select the difficulty level for each Sudoku puzzle you unlock - select Quick or Super Quick difficulty to have more numbers filled in at the start of the puzzle.
Tap on a grid square to select it, then use the keypad buttons below the grid to enter numbers.
The top row of buttons enter numbers in pen (indicating that they're part of the final answer). The bottom row allow you to enter numbers in pencil, to help keep track of which numbers are still valid for that square.
You can erase numbers you've entered by reselecting the square you want to edit, and using the keypad buttons to 'switch off' (erase) entered numbers.

Extra help

If you're stuck on a Sudoku puzzle, you can use coins to buy hints.
Hints can be used by tapping on the relevant icon in the status bar area at the top of the screen.
The cost (in coins) to use each hint is printed under its icon.
■ Solve Cell
Use this hint to put the correct number into this cell only.
■ Show Pencil Numbers
Use this hint to fill in all pencil marks showing which possible numbers are valid in that location.
■ Check for Errors
Use this hint to highlight all the cells with incorrect values.