Select the number first, then tap the cells to place it quickly.
Sudoku teaches you the invaluable logical art of the process of elimination. sudoku 129 better
The digit in Column 9 tells you which column the number 9 is in for that row. Select the number first, then tap the cells
box contain the exact same two candidates (and no others), those two numbers are locked into those cells. You can safely remove them from the rest of the unit. Select the number first