| Junior Puzzle #10 - One Possible Solution Approach… | |||||||||||
| NB: There is only one final solution to this Sudoku puzzle… | |||||||||||
| 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 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | Junior Puzzle #10 - November 16, 2005 | |||
| 2 | 3 | 2 | 9 | 4 | 6 | Original puzzle as published © joe-ks.com | |||||
| 3 | 1 | 5 | 2 | 3 | 9 | 8 | 4 | ||||
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | ||||
| 6 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | ||||
| 7 | 4 | 9 | 5 | 6 | 3 | 2 | |||||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | Step 1: Complete Column B: #7 MUST go in Cell B2... | |||
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | ||
| 3 | 1 | 5 | 2 | 3 | 9 | 8 | 4 | Step 2: Complete Column C: #8 MUST go in Cell C2... | |||
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | Step 3: Complete Column G: #1 MUST go in Cell G2... | |||
| 6 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | ||||
| 7 | 4 | 9 | 5 | 6 | 3 | 2 | Step 4: Complete Column H: #5 MUST go in Cell H2... | ||||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 5: Complete Block AA: #9 MUST go in Cell A1... | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | ||
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | Step 6: Complete Block CC: #3 MUST go in Cell I1... | |
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | Step 7: Complete Block DD: need #s 6 & 7… | |||
| 6 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | #7 can't go in Cell D3 (cf #7 in Column D @ D6), so | |||
| 7 | 4 | 9 | 5 | 6 | 3 | 2 | #7 MUST go in Cell G3, & therefore #6 MUST go in Cell D3 | ||||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 8: Complete Column A: need #s 5 & 7… | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | #5 can't go in Cell A5 (cf #5 in Row 5 @ D5), so | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | #5 MUST go in Cell A6, & therefore #7 MUST go in Cell A5 | |
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | Step 9: Complete Row 5: #9 MUST go in Cell I5... | |
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 6 | 3 | 2 | Step 10: Complete Row 6: #1 MUST go in Cell I6… | ||||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 11: #8 is in Columns E & F: #8 MUST go in Cell D7 | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | (#8 in Row 8 @ G8 excludes use of Cell D8, & | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | #8 in Row 9 @ A9 excludes use o fCell D9) | |
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 6 | 3 | 2 | ||||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 12: #7 is in Columns D & F: #7 MUST go in Cell E7 | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | (#7 in Row 9 @ C9 excludes use of Cell E9) | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | ||
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 6 | 3 | 2 | |||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 4 | 1 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 13: #9 is in Columns E & F: #9 MUST go in Cell D9 | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | (#9 in Row 8 @ H8 excludes use of Cell D8) | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | ||
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 6 | 3 | 2 | |||
| 8 | 6 | 3 | 1 | 5 | 8 | 9 | 7 | ||||
| 9 | 8 | 2 | 7 | 9 | 4 | 1 | 5 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 14: Complete Row 8: need #s 2 & 4… | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | #2 can’t go in Cell D8 (cf #2 in Column D @ D2), so | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | #2 MUST go in Cell F8, & therefore #4 MUST go in Cell D8 | |
| 4 | 2 | 1 | 9 | 5 | 7 | 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 6 | 3 | 2 | |||
| 8 | 6 | 3 | 1 | 4 | 5 | 2 | 8 | 9 | 7 | ||
| 9 | 8 | 2 | 7 | 9 | 4 | 1 | 5 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 15: Complete Column D: #3 MUST go in Cell D4... | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | ||
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | Step 16: Complete Row 7: #1 MUST go in Cell F7... | |
| 4 | 2 | 1 | 9 | 3 | 5 | 7 | 8 | ||||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 1 | 6 | 3 | 2 | ||
| 8 | 6 | 3 | 1 | 4 | 5 | 2 | 8 | 9 | 7 | ||
| 9 | 8 | 2 | 7 | 9 | 4 | 1 | 5 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 17: Complete Block EE: need #s 4 & 6… | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | #4 can’t go in Cell F4 (cf #4 in Collumn F @ F2), so | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | #4 MUST go in Cell D4, & therefore #6 MUST go in Cell F4 | |
| 4 | 2 | 1 | 9 | 3 | 4 | 6 | 5 | 7 | 8 | ||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 1 | 6 | 3 | 2 | ||
| 8 | 6 | 3 | 1 | 4 | 5 | 2 | 8 | 9 | 7 | ||
| 9 | 8 | 2 | 7 | 9 | 4 | 1 | 5 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | Step 18: Complete Block HH (& Puzzle): need #s 3 & 6… | |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | #6 can't go in Cell F9 (cf #6 in Column F @ F4), so | |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | #6 MUST go in Cell E9, & therefore #3 MUST go in Cell F9 | |
| 4 | 2 | 1 | 9 | 3 | 4 | 6 | 5 | 7 | 8 | ||
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | ||
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | ||
| 7 | 4 | 9 | 5 | 8 | 7 | 1 | 6 | 3 | 2 | ||
| 8 | 6 | 3 | 1 | 4 | 5 | 2 | 8 | 9 | 7 | ||
| 9 | 8 | 2 | 7 | 9 | 6 | 3 | 4 | 1 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 9 | 4 | 6 | 1 | 8 | 5 | 7 | 2 | 3 | 45 | Final Proof: |
| 2 | 3 | 7 | 8 | 2 | 9 | 4 | 1 | 5 | 6 | 45 | - All Rows add up to 45; |
| 3 | 1 | 5 | 2 | 6 | 3 | 7 | 9 | 8 | 4 | 45 | |
| 4 | 2 | 1 | 9 | 3 | 4 | 6 | 5 | 7 | 8 | 45 | |
| 5 | 7 | 6 | 3 | 5 | 1 | 8 | 2 | 4 | 9 | 45 | |
| 6 | 5 | 8 | 4 | 7 | 2 | 9 | 3 | 6 | 1 | 45 | |
| 7 | 4 | 9 | 5 | 8 | 7 | 1 | 6 | 3 | 2 | 45 | |
| 8 | 6 | 3 | 1 | 4 | 5 | 2 | 8 | 9 | 7 | 45 | |
| 9 | 8 | 2 | 7 | ||||||||