Entering numbers and pencil marks

There are three ways by which you can enter values and pencil marks into the cells:

The keyboard.
The big selector.
The small selector.

Using the keyboard

The keyboard, along with the big selector are the default interfaces that are enabled when you use the player for the first time.

To enter numbers using the keyboard hover the mouse over the cell that you want to update. A blue tinted circles appears inside the cell when you roll the cursor over as it becomes active and disappear when you roll the cursor out.
Press a number on the keyboard to enter a new number or to replace one that you entered previously.
To delete a number (clear the cell) press the backspace or delete key.
To enter a pencil mark press the space key to toggle to pencil mark mode and press the number you want to enter.
The circle that highlights the active cell turns light grey in pencil mark mode and light blue in normal mode.
From pencil mark mode, press space again to go back to normal mode.
When the cursor is over the grid you can also use the up/down/left/right arrow keys to navigate between the cells

The big selector

The big selector appears when you left-click with your mouse on the currently active cell, regardless whether you are in pencil mark mode or normal mode.

To enter a normal number click over one of the big keys marked 1 to 9.
To erase a normal number click over the key marked "Erase".
To toggle pencil marks click on the tiny number keys on the bottom left of the selector.
To change the background color of a cell, click on one of the coloured buttons that appear on the top-right of the selector panel.
To reset the background color to white, press the key marked "White"
The big selector is the only control that enables you to change the background of the grid cells. This is useful for applying the 'colouring' techniques sometimes used for solving the most difficult puzzles.

The big selector closes when you enter a new number (not a pencil mark) or if you hover out of it for more than 1 second or if you click on the close button identified by a small x at the top right corner of the panel.

The small selector

The small selector is the fastest way to interact with the sudoku grid if you prefer to maximise the use of the mouse over the keyboard. The keyboard cannot be used with the small selector.

The small selector is enabled through the options panel.

Once enabled it appears automatically as you hover over the cells in the grid.

To enter or replace a normal number in a cell, left-click over the new number with your mouse.
To delete a normal number from a cell, left-click over the same number.
To toggle a pencil mark left-click over the number while holding down the shift key. The pencil marks that are set are shown in bold.

To hide the small selector temporarily, and take a better view of the puzzle, move the cursor outside of the grid.