Number 8 is the only value possible in cell (3,3).

Number 9 is the only value possible in cell (3,8).

Number 3 is the only value possible in cell (3,7).

Number 4 is the only value possible in cell (3,9).

Number 1 is the only value possible in cell (3,5).

Number 6 is the only value possible in cell (8,9).

Number 8 is the only value possible in cell (8,8).

Number 2 is the only value possible in cell (9,7).

Number 1 is the only value possible in cell (7,7).

For row 3, number 3 is only possible in cell (8,3)

For row 5, number 3 is only possible in cell (6,5)

For row 6, number 3 is only possible in cell (2,6)

For column 9, Number 6 is only possible in cell (9,3)

For column 9, Number 7 is only possible in cell (9,5)

For box 3, candidates for 5 are all in row 1, so you can remove candidates from other blocks.

For box 1, candidates for 4 are all in column 2, so you can remove candidates from other blocks.

For box 8, candidates for 2 are all in row 8, so you can remove candidates from other blocks.

Naked Pair for 5 and 8, can remove these as candidates from other cells.

Hidden Pair for 2 and 7, can remove other candidates from these cells.

Either candidate for cell (4,2) forces 2 into cell (6,4).

Number 6 is the only value possible in cell (6,8).

Number 8 is the only value possible in cell (6,2).

Number 1 is the only value possible in cell (5,1).

Number 6 is the only value possible in cell (4,2).

Number 5 is the only value possible in cell (4,5).

Number 9 is the only value possible in cell (6,6).

Number 5 is the only value possible in cell (6,3).

Number 9 is the only value possible in cell (5,3).

Number 1 is the only value possible in cell (4,4).

Number 4 is the only value possible in cell (5,4).

Number 9 is the only value possible in cell (8,4).

Number 7 is the only value possible in cell (4,6).

Number 8 is the only value possible in cell (5,6).

Number 6 is the only value possible in cell (5,5).

Number 9 is the only value possible in cell (4,7).

Number 5 is the only value possible in cell (5,7).

Number 8 is the only value possible in cell (1,7).

Number 4 is the only value possible in cell (1,5).

Number 8 is the only value possible in cell (7,5).

Number 5 is the only value possible in cell (9,4).

Number 8 is the only value possible in cell (9,1).

Number 8 is the only value possible in cell (2,4).

Number 5 is the only value possible in cell (1,6).

Number 4 is the only value possible in cell (8,6).

Number 5 is the only value possible in cell (8,1).

Number 1 is the only value possible in cell (8,2).

Number 6 is the only value possible in cell (2,7).

Number 7 is the only value possible in cell (2,8).

Number 4 is the only value possible in cell (2,2).

Number 2 is the only value possible in cell (2,1).

Number 4 is the only value possible in cell (7,1).

Number 7 is the only value possible in cell (7,2).

Number 7 is the only value possible in cell (1,3).

Number 2 is the only value possible in cell (7,3).

Number 2 is the only value possible in cell (4,8).

Number 2 is the only value possible in cell (1,9).

Number 5 is the only value possible in cell (2,9).

Number 7 is the only value possible in cell (5,9).