Notes on this puzzle
Sudoku #5104 is an easy grid with 37 givens, which leaves 44 cells waiting for a digit. Played purely by logic, it takes 44 forced steps from the first placement to the last.
Nothing beyond hidden single is needed anywhere, so the whole grid is a scanning exercise.
Among the givens, 1 is the most common digit (6 times) and 4 the rarest (3). The emptiest box is the top-left one, with 1 given; the central box is the most crowded, with 7.
Where to beginLook at row 2, column 2 first: a hidden single is available there from the very start. Scan digit by digit; notes are hardly needed here.