Goal: Fill the 9x9 grid with digits so that each column, each row, and each of the nine 3x3 subgrids contain all of the digits from 1 to 9.

• Select an empty cell and use the on-screen Numpad or your Keyboard to enter a number.
• If you enter a number that violates the rules, it will be marked in red as a mistake.
• Toggle Note Mode (✏️) to pencil in possible numbers for a cell instead of making a final guess.
• You win when the entire board is filled correctly!