Variations on Junior Sudoku Logic Puzzles (Vol 1) 
 Chapter 30: Twenty-Seven Easy Sudoku-6up Puzzles (numbers 625-651) 
 
-  Step-by-step instructions for solving  Puzzle 625, (14/36)   Diff: 3/743
 -  Step-by-step instructions for solving  Puzzle 626, (14/36)   Diff: 3/653
 -  Step-by-step instructions for solving  Puzzle 627, (17/36)   Diff: 3/953
 -  Step-by-step instructions for solving  Puzzle 628, (18/36)   Diff: 3/961
 -  Step-by-step instructions for solving  Puzzle 629, (18/36)   Diff: 3/951
 -  Step-by-step instructions for solving  Puzzle 630, (18/36)   Diff: 3/855
 -  Step-by-step instructions for solving  Puzzle 631, (19/36)   Diff: 3/981
 -  Step-by-step instructions for solving  Puzzle 632, (20/36)   Diff: 3/991
 -  Step-by-step instructions for solving  Puzzle 633, (20/36)   Diff: 3/991
 -  Step-by-step instructions for solving  Puzzle 634, (20/36)   Diff: 3/982
 -  Step-by-step instructions for solving  Puzzle 635, (20/36)   Diff: 3/971
 -  Step-by-step instructions for solving  Puzzle 636, (20/36)   Diff: 3/962
 -  Step-by-step instructions for solving  Puzzle 637, (21/36)   Diff: 3/992
 -  Step-by-step instructions for solving  Puzzle 638, (21/36)   Diff: 3/992
 -  Step-by-step instructions for solving  Puzzle 639, (21/36)   Diff: 3/991
 -  Step-by-step instructions for solving  Puzzle 640, (22/36)   Diff: 3/994
 -  Step-by-step instructions for solving  Puzzle 641, (20/36)   Diff: 4/9541
 -  Step-by-step instructions for solving  Puzzle 642, (21/36)   Diff: 4/9741
 -  Step-by-step instructions for solving  Puzzle 643, (21/36)   Diff: 4/9441
 -  Step-by-step instructions for solving  Puzzle 644, (21/36)   Diff: 4/7572
 -  Step-by-step instructions for solving  Puzzle 645, (22/36)   Diff: 4/9642
 -  Step-by-step instructions for solving  Puzzle 646, (22/36)   Diff: 4/8743
 -  Step-by-step instructions for solving  Puzzle 647, (23/36)   Diff: 4/9941
 -  Step-by-step instructions for solving  Puzzle 648, (23/36)   Diff: 4/9734
 -  Step-by-step instructions for solving  Puzzle 649, (23/36)   Diff: 4/8672
 -  Step-by-step instructions for solving  Puzzle 650, (24/36)   Diff: 4/7692
 -  Step-by-step instructions for solving  Puzzle 651, (26/36)   Diff: 4/8864