Easy Puzzle #21 - One Possible Solution Approach…
	NB:  There is only one final solution to this Sudoku puzzle…
	Rules: Place a number from 1-9 in each empty cell so that each row, each column AND each 3x3 block contains all the numbers from 1-9.
	A	B	C	D	E	F	G	H	I
1
2	AA			BB			CC				Reference to 3x3 Blocks AA, BB & CC
3
4
5	DD			EE			FF				Reference to 3x3 Blocks DD, EE & FF
6
7
8	GG			HH			II				Reference to 3x3 Blocks GG, HH & II
9
	A	B	C	D	E	F	G	H	I
1			8		3		2		4		Easy Puzzle #21 - October 21, 2005
2	2	1		7	4						Original puzzle as published on joe-ks.com…
3				6	8			7
4		5			7				8
5	7	9		5	1			2
6	8		3			6	5	1
7		8		3	2		9	5
8		6			5				1
9			9	8		1	7	3
	A	B	C	D	E	F	G	H	I
1			8		3		2		4		Step 1: #2 is in Rows 1 & 2: #2 MUST go in Cell F3…
2	2	1		7	4
3				6	8	2		7
4		5			7				8		Step 2: #7 is in Rows 4 & 5: #7 MUST go in Cell I6…
5	7	9		5	1			2
6	8		3			6	5	1	7
7		8		3	2		9	5			Step 3: #3 is in Rows 7 & 9: #3 MUST go in Cell A8
8	3	6			5				1		(cf #3 in Column C @ C6 excludes use of Cell C8)
9			9	8		1	7	3
	A	B	C	D	E	F	G	H	I
1			8		3		2		4		Step 4: #3 is in Columns A & C: #3 MUST go in Cell B3
2	2	1		7	4						(cf #3 in Row 1 @ E1 excludes use of Cell B1)
3		3		6	8	2		7
4		5			7				8		Step 5: #6 is in Columns D & F: #6 MUST go in Cell E9…
5	7	9		5	1			2
6	8		3			6	5	1	7
7		8		3	2		9	5
8	3	6			5				1
9			9	8	6	1	7	3
	A	B	C	D	E	F	G	H	I
1			8		3		2		4		Step 6: Complete Column E: #9 MUST go in Cell E6…
2	2	1		7	4
3		3		6	8	2	1	7
4		5			7				8		Step 7: #1 is in Columns H & I: #1 MUST go in Cell G3
5	7	9		5	1			2			(cf #1 in Row 2 @ B2 excludes use of Cell G2)
6	8		3		9	6	5	1	7
7		8		3	2		9	5
8	3	6			5				1
9			9	8	6	1	7	3
	A	B	C	D	E	F	G	H	I
1		7	8		3		2		4		Step 8: #7 is in Rows 2 & 3: #7 MUST go in Cell B1
2	2	1		7	4						(cf #7 in Column A @ A5 excludes use of Cell A1)
3		3		6	8	2	1	7
4		5			7				8		Step 9: #6 is in Rows 8 & 9: #6 MUST go in Cell I7…
5	7	9		5	1			2
6	8		3		9	6	5	1	7
7		8		3	2		9	5	6
8	3	6			5				1
9			9	8	6	1	7	3
	A	B	C	D	E	F	G	H	I
1		7	8	1	3		2		4		Step 10: #1 is in Rows 2 & 3: #1 MUST go in Cell D1
2	2	1		7	4						(cf #1 in Column F @ F9 excludes use of Cell F1)
3		3		6	8	2	1	7
4		5			7			9	8		Step 11: #9 is in Rows 5 & 6: #9 MUST go in Cell H4
5	7	9		5	1			2			(cf #9 in Column G @ G7 excludes use of Cell G4)
6	8		3		9	6	5	1	7
7		8		3	2		9	5	6
8	3	6			5				1
9			9	8	6	1	7	3
	A	B	C	D	E	F	G	H	I
1		7	8	1	3		2		4		Step 12: Column H needs #4: #4 MUST go in Cell H8
2	2	1		7	4						(#4 in Row 1 @ I1 excludes Cell H1, & #4 in Row 2 @ E2
3		3		6	8	2	1	7			excludes Cell H2)
4		5			7			9	8
5	7	9		5	1			2
6	8		3		9	6	5	1	7
7		8		3	2		9	5	6
8	3	6			5			4	1
9			9	8	6	1	7	3
	A	B	C	D	E	F	G	H	I
1		7	8	1	3		2		4		Step 13: Complete Block II: need #s 2 & 8…
2	2	1		7	4						#8 can't go in Cell I9 (cf #8 in Row 9 @ D9), so
3		3		6	8	2	1	7			#8 MUST go in Cell G8, & therefore #2 MUST go in Cell I9
4		5			7			9	8
5	7	9		5	1			2			Step 14: Complete Column B: need #s 2 & 4…
6	8	2	3		9	6	5	1	7		#2 can't go in Cell B8 (see #2 from Step 13 @ I9), so
7		8		3	2		9	5	6		#2 MUST go in Cell B6, & therefore #4 MUST go in Cell B8
8	3	6			5		8	4	1
9		4	9	8	6	1	7	3	2
	A	B	C	D	E	F	G	H	I
1		7	8	1	3		2	6	4		Step 15: Complete Row 9: #5 MUST go in Cell A9…
2	2	1		7	4			8
3		3		6	8	2	1	7			Step 16: Complete Column H: need #s 6 & 8…
4		5			7			9	8		#8 can't go in Cell H1 (cf #8 in Row 1 @ C1), so
5	7	9		5	1			2			#8 MUST go in Cell H2, & therefore #6 MUST go in Cell H1
6	8	2	3		9	6	5	1	7
7		8		3	2		9	5	6
8	3	6			5		8	4	1
9	5	4	9	8	6	1	7	3	2
	A	B	C	D	E	F	G	H	I
1	9	7	8	1	3	5	2	6	4		Step 17: Complete Row 1: need #s 5 & 9…
2	2	1		7	4			8			#5 can’t go in Cell A1 (cf #5 in Column A @ A9), so
3		3		6	8	2	1	7			#5 MUST go in Cell F1, & therefore #9 MUST go in Cell A1
4		5			7			9	8
5	7	9		5	1			2			Step 18: Complete Row 6: #4 MUST go in Cell D6…
6	8	2	3	4	9	6	5