Easy Puzzle #13 - 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				3	5			6			Easy Puzzle #13 - October 13, 2005
2		5	6	2		8	3		4		Original puzzle as published on joe-ks.com…
3	2	3						7
4		8		5
5		9		4	3		2	8	1
6	7				9			5
7		7	4		8	1	9
8		6					8	4
9	3	2		9	4		6	1
	A	B	C	D	E	F	G	H	I
1				3	5			6	2		Step 1: #2 is in Rows 2 & 3: #2 MUST go in Cell I1
2		5	6	2		8	3		4		(cf #2 in Column G @ G5 excludes use of Cell G1)
3	2	3						7
4		8		5							Step 2: #6 is in Rows 8 & 9: #6 MUST go in Cell D7…
5		9		4	3		2	8	1
6	7				9			5
7		7	4		8	1	9
8		6					8	4
9	3	2		9	4		6	1
	A	B	C	D	E	F	G	H	I
1			7	3	5			6	2		Step 3: #7 is in Columns A & B: #7 MUST go in Cell C1
2		5	6	2		8	3		4		(cf #7 in Row 3 @ Cell h3 excludes use of Cell C3)
3	2	3						7	8
4		8		5
5		9		4	3		2	8	1		Step 4: #8 is in Columns G & H: #8 MUST go in Cell I3…
6	7				9			5
7		7	4		8	1	9
8		6					8	4
9	3	2		9	4		6	1
	A	B	C	D	E	F	G	H	I
1			7	3	5			6	2		Step 5: #5 is in Rows 1 & 2: #5 MUST go in Cell G3…
2		5	6	2		8	3		4
3	2	3					5	7	8		Step 6: #5 is in Rows 4 & 6: #5 MUST go in Cell C6
4		8		5							(cf #5 in Column B @ B2 excludes use of Cell B6)
5		9	5	4	3		2	8	1
6	7				9			5			Step 7: #8 is in Rows 7 & 8: #8 MUST go in Cell C9…
7		7	4		8	1	9
8		6					8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8		7	3	5		1	6	2		Step 8: #8 is in Columns B & C: #8 MUST go in Cell A1
2		5	6	2		8	3		4		(cf #8 in Row 2 @ F2 excludes use of Cell A2)
3	2	3					5	7	8
4		8		5
5		9	5	4	3		2	8	1		Step 9: #1 is in Columns H & I: #9 MUST go in Cell G1…
6	7				9			5
7		7	4		8	1	9
8		6					8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5		1	6	2		Step 10: Complete Block CC: #9 MUST go in Cell H2…
2		5	6	2		8	3	9	4
3	2	3					5	7	8		Step 11: #8 is in Columns E & F: #8 MUST go in Cell D6…
4		8		5
5		9	5	4	3		2	8	1		Step 12: Block AA needs #4: #4 MUST go in Cell B1
6	7			8	9			5			(#4 in Row 2 @ I2 excludes Cell A2, & #4 in Column C @
7		7	4		8	1	9				C7 excludes Cell C3)
8		6					8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 13: Complete Column B: #1 MUST go in Cell B6…
2		5	6	2		8	3	9	4
3	2	3					5	7	8		Step 14: Complete Row 1: #9 MUST go in Cell F1…
4		8		5
5		9	5	4	3		2	8	1
6	7	1		8	9			5
7		7	4		8	1	9
8		6					8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 15: #7 is in Rows 1 & 3: #7 MUST go in Cell E2…
2		5	6	2	7	8	3	9	4
3	2	3					5	7	8
4		8		5	1						Step 16: Block EE needs #1: #1 MUST go in Cell E4…
5		9	5	4	3		2	8	1		(#1 in Column F @ F7 excludes use of F4, F5 & F6)
6	7	1		8	9			5
7		7	4		8	1	9	2			Step 17: Block II needs #2: #2 MUST go in Cell H7…
8		6					8	4			(#2 in Column I @ I1 excludes use of I7, I8 & I9)
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 18: Complete Row 2: #1 MUST go in Cell A2…
2	1	5	6	2	7	8	3	9	4
3	2	3					5	7	8		Step 19: #9 is in Rows 5 & 6: #9 MUST go in Cell I4…
4		8		5	1				9		(#9 in Column G @ G7 excludes G4, & #9 in Column H @
5		9	5	4	3		2	8	1		H2 excludes H4)
6	7	1		8	9			5
7		7	4		8	1	9	2
8		6					8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 20: Complete Block AA: #9 MUST go in Cell C3…
2	1	5	6	2	7	8	3	9	4
3	2	3	9				5	7	8		Step 21: Complete Column H: #3 MUST go in Cell H4…
4		8		5	1			3	9
5		9	5	4	3		2	8	1		Step 22: #1 is in Column A & B: #1 MUST go in Cell C8…
6	7	1		8	9			5
7		7	4		8	1	9	2
8		6	1				8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 23: Complete Column C: need #s 2 & 3…
2	1	5	6	2	7	8	3	9	4		#3 can't go in Cell C4 (cf #3 in Row 4 @ H3), so
3	2	3	9				5	7	8		#3 MUST go in Cell C6, & therefore #2 MUST go in Cell C4
4		8	2	5	1			3	9
5		9	5	4	3		2	8	1
6	7	1	3	8	9			5
7		7	4		8	1	9	2
8		6	1				8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 24: Complete Column E: Need #s 2 & 6…
2	1	5	6	2	7	8	3	9	4		#2 can't go in Cell E3 (cf #2 in Row 2 @ A3), so
3	2	3	9		6		5	7	8		#2 MUST go in Cell E8, & therefore #6 MUST go in Cell E3
4		8	2	5	1			3	9
5		9	5	4	3		2	8	1		Step 25: #6 is in Columns G & H: #6 MUST go in Cell I6…
6	7	1	3	8	9			5	6
7		7	4		8	1	9	2
8		6	1		2		8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 26: Complete Row 5: need #s 6 & 7…
2	1	5	6	2	7	8	3	9	4		#7 can't go in Cell A5 (cf #7 in Column A @ A6), so
3	2	3	9	1	6	4	5	7	8		#7 MUST go in Cell F5, & therefore #6 MUST go in Cell A5
4		8	2	5	1			3	9
5	6	9	5	4	3	7	2	8	1		Step 27: Complete Row 3: need #s 1 & 4…
6	7	1	3	8	9			5	6		#4 can't go in Cell D3 (cf #4 in Column D @ D5), so
7		7	4		8	1	9	2			#4 MUST go in Cell F4, & therefore #1 MUST go in Cell D3
8		6	1		2		8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 28: Complete Block DD: #4 MUST go in Cell A4…
2	1	5	6	2	7	8	3	9	4
3	2	3	9	1	6	4	5	7	8		Step 29: Complete Block FF: need #s 4 & 7…
4	4	8	2	5	1		7	3	9		#4 can't go in Cell G4 (see Step 28), so
5	6	9	5	4	3	7	2	8	1		#4 MUST go in Cell G6, & therefore #7 MUST go in Cell G4
6	7	1	3	8	9		4	5	6
7		7	4		8	1	9	2
8		6	1		2		8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 30: Complete Row 4: #6 MUST go in Cell F4…
2	1	5	6	2	7	8	3	9	4
3	2	3	9	1	6	4	5	7	8		Step 31: Complete Row 6: #2 MUST go in Cell F6…
4	4	8	2	5	1	6	7	3	9
5	6	9	5	4	3	7	2	8	1		Step 32: Complete Block GG: need #s 5 & 9…
6	7	1	3	8	9	2	4	5	6		#9 can't go in Cell A7 (cf #9 in Row 7 @ G7), so
7	5	7	4		8	1	9	2			#9 MUST go in Cell A8, & therefore #5 MUST go in Cell A7
8	9	6	1		2		8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 33: Complete Column D: need #s 6 & 7…
2	1	5	6	2	7	8	3	9	4		#7 can't go in Cell D7 (cf #7 in Row 7 @ B7), so
3	2	3	9	1	6	4	5	7	8		#7 MUST go in Cell D8, & therefore #6 MUST go in Cell D7
4	4	8	2	5	1	6	7	3	9
5	6	9	5	4	3	7	2	8	1
6	7	1	3	8	9	2	4	5	6
7	5	7	4	6	8	1	9	2
8	9	6	1	7	2		8	4
9	3	2	8	9	4		6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 34: Complete Row 7: #3 MUST go in Cell I7…
2	1	5	6	2	7	8	3	9	4
3	2	3	9	1	6	4	5	7	8		Step 35: Complete Column F: need #s 3 & 5…
4	4	8	2	5	1	6	7	3	9		#3 can't go in Cell F9 (cf #3 in Row 9 @ A9), so
5	6	9	5	4	3	7	2	8	1		#3 MUST go in Cell F8, & therefore #5 MUST go in Cell F9
6	7	1	3	8	9	2	4	5	6
7	5	7	4	6	8	1	9	2	3
8	9	6	1	7	2	3	8	4
9	3	2	8	9	4	5	6	1
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2		Step 36: Complete Row 8: #5 MUST go in Cell I8…
2	1	5	6	2	7	8	3	9	4
3	2	3	9	1	6	4	5	7	8		Step 37: Complete Row 9, Column I & Block II:
4	4	8	2	5	1	6	7	3	9		#7 MUST go in Cell I9.
5	6	9	5	4	3	7	2	8	1
6	7	1	3	8	9	2	4	5	6
7	5	7	4	6	8	1	9	2	3
8	9	6	1	7	2	3	8	4	5
9	3	2	8	9	4	5	6	1	7
	A	B	C	D	E	F	G	H	I
1	8	4	7	3	5	9	1	6	2	45	Final Proof:
2	1	5	6	2	7	8	3	9	4	45	- All Rows add up to 45;
3	2	3	9	1	6	4	5	7	8	45
4	4	8	2	5	1	6	7	3	9	45
5	6	9	5	4	3	7	2	8	1	45
6	7	1	3	8	9	2	4	5	6	45
7	5	7	4	6	8	1	9	2	3	45
8	9	6	1	7	2	3	8	4	5	45
9	3	2	8	9	4	5	6	1	7	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