How to Play
𧊠The Rule
Every row, every column, and every 2Ã2 box must contain the numbers 1, 2, 3, and 4 â each exactly once. No number can repeat!
đ How to Fill In
Tap an empty box to select it, then tap a number below the grid to fill it in. Tap â to erase a box.
đ A Good Trick
Look at a row, column, or box that's almost full â if three of the four numbers are already there, you know exactly what the missing one has to be!