Easy Puzzle #25 - 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		1	9		3		6	4			Easy Puzzle #25 - October 25, 2005  © joe-ks.com
2	3	4						7	1		One possible Solution Method follows below…
3				1	9	4
4			6	3			4
5	9		4		5		1		7
6			7		8	9	2
7				5	7	3
8	2	7		8				9	6
9		8			6			1
	A	B	C	D	E	F	G	H	I
1		1	9		3		6	4			Step 1: #9 is in Rows 1 & 2: #9 MUST go in Cell G2…
2	3	4					9	7	1
3				1	9	4
4			6	3			4				Step 2: #4 is in Rows 4 & 5: #4 MUST go in Cell D6…
5	9		4		5		1		7
6			7	4	8	9	2
7				5	7	3					Step 3: #7 is in Rows 7 & 8: #7 MUST go in Cell G9
8	2	7		8				9	6		(cf #7 in Column I @ I5 excludes use of Cell I9)
9		8			6		7	1
	A	B	C	D	E	F	G	H	I
1		1	9		3		6	4			Step 4: #9 is in Columns A & C: #9 MUST go in Cell B7…
2	3	4					9	7	1
3				1	9	4
4			6	3			4		9		Step 5: #4 is in Columns D & F: #4 MUST go in Cell E8…
5	9		4		5		1		7
6			7	4	8	9	2
7		9		5	7	3					Step 6: #9 is in Columns G & H: #9 MUST go in Cell I4
8	2	7		8	4			9	6		(cf #9 in Row 6 @ F6 excludes use of Cell I6)
9		8			6		7	1
	A	B	C	D	E	F	G	H	I
1		1	9		3		6	4			Step 7: Complete Column E: need #s 1 & 2…
2	3	4			2		9	7	1		#1 can't go in Cell E2 (cf #1 in Row 2 @ I2), so
3				1	9	4					#1 MUST go in Cell E4, & therefore #2 MUST go in Cell E2
4			6	3	1		4		9
5	9		4		5		1		7
6			7	4	8	9	2
7		9		5	7	3
8	2	7		8	4			9	6
9		8			6		7	1
	A	B	C	D	E	F	G	H	I
1		1	9		3		6	4			Step 8: #1 is in Columns D & E: #1 MUST go in Cell F8
2	3	4			2		9	7	1		(cf #1 in Row 9 @ H9 excludes use of Cell F9)
3				1	9	4
4			6	3	1		4		9
5	9		4		5		1		7
6			7	4	8	9	2
7		9		5	7	3
8	2	7		8	4	1		9	6
9		8			6		7	1
	A	B	C	D	E	F	G	H	I
1		1	9		3		6	4			Step 9: Complete Block HH: need #s 2 & 9…
2	3	4			2		9	7	1		#9 can't go in Cell F9 (cf #9 in Column F @ F6), so
3				1	9	4					#9 MUST go in Cell D9, & therefore #2 MUST go in Cell F9
4			6	3	1		4		9
5	9		4	2	5		1		7		Step 10: Now #2 is in Columns E & F: #2 MUST go in Cell D5
6			7	4	8	9	2
7		9		5	7	3
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 11: Complete Block EE: need #s 6 & 7…
2	3	4			2		9	7	1		#6 can't go in Cell F4 (cf #6 in Row 4 @ C4), so
3				1	9	4					#6 MUST go in Cell F5, & therefore #7 MUST go in Cell F4
4			6	3	1	7	4		9
5	9		4	2	5	6	1		7		Step 12: Now #7 is in Columns E & F: #7 MUST go in Cell D1
6			7	4	8	9	2				(cf #7 in Row 2 @ H2 excludes use of Cell D2)
7		9		5	7	3
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 13: Complete Column D: #6 MUST go in Cell D2…
2	3	4		6	2		9	7	1
3				1	9	4
4			6	3	1	7	4		9		Step 14: Complete Row 5: need #s 3 & 8…
5	9	3	4	2	5	6	1	8	7		#8 can't go in Cell B5 (cf #8 in Column B @ B9), so
6			7	4	8	9	2				#8 MUST go in Cell H5, & therefore #3 MUST go in Cell B5
7		9		5	7	3
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 15: Row 4 needs #8: #8 MUST go in Cell A4
2	3	4		6	2		9	7	1		(cf #8 in Column B @ B9 excludes use of Cell B4, &
3	7			1	9	4					#8 in Column H @ H5 excludes use of Cell H4)
4	8		6	3	1	7	4		9
5	9	3	4	2	5	6	1	8	7		Step 16: #7 is in Rows 1 & 2: #7 MUST go in Cell A3
6			7	4	8	9	2				(#7 in Column B @ B8 excludes use of Cell B3, &
7		9		5	7	3					#7 in Column C @ C6 excludes use of Cell C3)
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 17: Block DD needs #1: #1 MUST go in Cell A6
2	3	4		6	2		9	7	1		(cf #1 in Column B @ B1 excludes use of Cells B4 & B6)
3	7			1	9	4
4	8		6	3	1	7	4		9		Step 18: #1 is now in Columns A & B: #1 MUST go in Cell C7
5	9	3	4	2	5	6	1	8	7		(#1 in Row 8 @ F8 excludes Cell C8, &
6	1		7	4	8	9	2				#1 in Row 9 @ H9 excludes Cell C9)
7		9	1	5	7	3
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 19: Complete Block DD: need #s 2 & 5…
2	3	4		6	2		9	7	1		#2 can't go in Cell B6 (cf #2 in Row 6 @ G6), so
3	7			1	9	4					#2 MUST go in Cell B4, & therefore #5 MUST go in Cell B6
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7		Step 20: #5 is now in Rows 5 & 6: #5 MUST go in Cell H4…
6	1	5	7	4	8	9	2
7		9	1	5	7	3
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1		1	9	7	3		6	4			Step 21: Complete Block FF: need #s 3 & 6…
2	3	4		6	2		9	7	1		#6 can't go in Cell I6 (cf #6 in Column I @ I8), so
3	7			1	9	4					#6 MUST go in Cell H6, & therefore #3 MUST go in Cell I6
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7
6	1	5	7	4	8	9	2	6	3
7	6	9	1	5	7	3					Step 22: #6 is in Rows 8 & 9: #6 MUST go in Cell A7…
8	2	7		8	4	1		9	6
9		8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3		6	4			Step 23: Complete Column A: need #s 4 & 5…
2	3	4		6	2		9	7	1		#4 can't go in Cell A1 (cf #4 in Row 1 @ H1), so
3	7			1	9	4					#4 MUST go in Cell A9, & therefore #5 MUST go in Cell A1
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7
6	1	5	7	4	8	9	2	6	3
7	6	9	1	5	7	3			4		Step 24: #4 is now in Rows 8 & 9: #4 MUST go in Cell I7
8	2	7		8	4	1		9	6		(#4 in Column G @ G4 excludes Cell G7, &
9	4	8		9	6	2	7	1			#4 in Column H @ H1 excludes Cell H7)
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4			Step 25: Complete Column F: need #s 5 & 8…
2	3	4		6	2	5	9	7	1		#5 can't go in Cell F1 (cf #5 in Row 1 @ A1), so
3	7			1	9	4					#5 MUST go in Cell F2, & therefore #8 MUST go in Cell F1
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7
6	1	5	7	4	8	9	2	6	3
7	6	9	1	5	7	3	8	2	4		Step 26: Complete Row 7: need #s 2 & 8…
8	2	7		8	4	1		9	6		#2 can't go in Cell G7 (cf #2 in Column G @ G6), so
9	4	8		9	6	2	7	1			#2 MUST go in Cell H7, & therefore #8 MUST go in Cell G7
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4	2		Step 27: Complete Row 1: #2 MUST go in Cell I1…
2	3	4	8	6	2	5	9	7	1
3	7			1	9	4					Step 28: Complete Row 2: #8 MUST go in Cell C2…
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7
6	1	5	7	4	8	9	2	6	3
7	6	9	1	5	7	3	8	2	4
8	2	7		8	4	1		9	6
9	4	8		9	6	2	7	1
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4	2		Step 29: Complete Column B: #6 MUST go in Cell B3…
2	3	4	8	6	2	5	9	7	1
3	7	6		1	9	4		3	8		Step 30: Complete Column H: #3 MUST go in Cell H3…
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7		Step 31: Complete Column I: need #s 5 & 8…
6	1	5	7	4	8	9	2	6	3		#8 can't go in Cell I9 (cf #8 in Row 9 @ B9), so
7	6	9	1	5	7	3	8	2	4		#8 MUST go in Cell I3, & therefore #5 MUST go in Cell I9
8	2	7		8	4	1		9	6
9	4	8		9	6	2	7	1	5
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4	2		Step 32: Complete Block GG: need #s 3 & 5…
2	3	4	8	6	2	5	9	7	1		#5 can't go in Cell C9 (cf #5 in Row 9 @ I9), so
3	7	6		1	9	4		3	8		#5 MUST go in Cell C8, & therefore #3 MUST go in Cell C9
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7		Step 33: #3 is now in Rows 7 & 9: #3 MUST go in Cell G8…
6	1	5	7	4	8	9	2	6	3
7	6	9	1	5	7	3	8	2	4
8	2	7	5	8	4	1		9	6
9	4	8	3	9	6	2	7	1	5
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4	2		Step 34: Complete Column C: #2 MUST go in Cell C3…
2	3	4	8	6	2	5	9	7	1
3	7	6	2	1	9	4	5	3	8
4	8	2	6	3	1	7	4	5	9
5	9	3	4	2	5	6	1	8	7		Step 35: Complete Column G (& Puzzle): need #s 3 & 5…
6	1	5	7	4	8	9	2	6	3		#3 can't go in Cell G3 (cf #3 in Row 3 @ H3), so
7	6	9	1	5	7	3	8	2	4		#3 MUST go in Cell G8, & therefore #5 MUST go in Cell G3
8	2	7	5	8	4	1	3	9	6
9	4	8	3	9	6	2	7	1	5
	A	B	C	D	E	F	G	H	I
1	5	1	9	7	3	8	6	4	2	45	Final Proof:
2	3	4	8	6	2	5	9	7	1	45	- All Rows add up to 45;
3	7	6	2	1	9	4	5	3	8	45
4	8	2	6	3	1	7	4	5	9	45
5	9	3	4	2	5	6	1	8	7	45
6	1	5	7	4	8	9	2	6	3	45
7	6	9	1	5	7	3	8	2	4	45
8	2	7	5	8	4	1	3	9	6	45
9	4	8	3	9	6	2	7	1	5	45
	45	45	45	45	45	45	45	45	45		- All Columns add up to 45;
	45			45			45				- All 3x3 Blocks add up to 45…
	45			45			45
	45			45			45