Free Sudoku for Windows, with notes and hints

Number Place is the 9 by 9 number puzzle in Games by Zaweba, free for Windows. Fill every empty cell so that each row, each column and each of the nine 3 by 3 boxes holds the digits 1 to 9 exactly once. Every puzzle has just one answer, and the app works offline with no adverts or account.

Number Place is the old name for this kind of puzzle, and it suits a puzzle that's all about logic rather than arithmetic. You never add anything up. You just work out which digit must go where.

How to play Number Place

Click a cell, then click a number on the pad, or type 1 to 9. Arrow keys move between cells and Backspace erases. Press P to switch to notes, so you can pencil small candidates into a cell while you work. H gives a hint and Z undoes your last move.

Your score is your time, plus 20 seconds for every mistake and 30 for every hint. That makes hints a real choice: they'll get you unstuck, but they cost you.

You'll find Number Place on the Puzzles shelf of Games by Zaweba, or press Ctrl+F in the library and type its name.

Solving techniques worth knowing

Scan for singles. Pick a digit, say 5, and look at each box. If the 5s already placed in nearby rows and columns leave only one cell in a box where a 5 can go, it goes there. Running through each digit like this fills in a lot of an easy puzzle.

Look for cells with one candidate. Sometimes a cell sees eight different digits in its row, column and box. The ninth must be the answer.

Use notes once the easy moves dry up. Pencilling candidates into empty cells shows patterns you can't keep in your head, such as two cells in a row that can only hold the same two digits. Those two digits then can't go anywhere else in that row.

Keep the notes tidy. Every time you place a digit, remove it from the notes of the cells in its row, column and box. Out-of-date notes are the commonest cause of mistakes.

Don't guess. Every puzzle has one answer, which means it can be solved by reasoning. If you find yourself guessing, step back and look for a pair or a single you've missed.

Getting a good score

Because your score is time plus penalties, speed matters, but accuracy matters more. A mistake costs 20 seconds and a hint 30, so a careful solve often beats a quick, error-strewn one. Undo is there for slips, and it's worth checking a digit before you commit.

Games by Zaweba keeps your best score for each game and mode, along with plays and wins, and the result card at the end shows your score next to your best. Scores are kept in a file in your own settings folder and never leave the PC.

A daily puzzle without fuss

Number Place makes a good daily habit. Star it so it sits on the Favourites shelf, or make a desktop shortcut that opens Games by Zaweba straight into it. Esc pauses whenever the kettle boils, and the puzzle pauses itself when you click into another window. F11 fills the screen, which makes the grid and your notes easier to read.

When you want a change, the Puzzles shelf has 11 more. Picture Grid reveals a hidden coloured picture from number clues, Hidden Mines is the mine-flagging logic grid, and Colour Code asks you to crack a hidden row of coloured pegs.