Use arrow keys to add numbers. Hold SHIFT to add number as a small note in the corner of a cell
Play this sudoku with your keyboard:
Use arrow-keys to navigate, press numbers to add them, hold SHIFT while entering the number to add it as a 'note' in the margin. Do it again to remove the note. Press BACKSPACE to clear the big number in a cell.
How to play sudoku - Beginner tips
The grey boxes are pre-filled numbers to help you get started
Add one number (1-9) per row, per column and per group (area with fat borders)
Start by looking at the areas with most pre-filled numbers. Find the missing number. Use SHIFT key to add 'notes' about each cell where that number could go.