Group Sum Sudoku Puzzles
Group Sum Sudoku is ideal for those who like sudoku variants, particularly rarely seen ones  you won't find group sum sudoku in too many places!
The rules of group sum sudoku are as follows:
Place each number from 19 once in each row, column and 3x3 box of the grid. In addition, there are various killer sudoku regions in the grid: these are uniform, and are composed of each group of four cells in each of the 3x3 boxes. Since showing these as orthodox killer sudoku regions would involve overlapping cages which would be very confusing to the eye, the regions are instead presented with the total at the intersection of the edges of the four cells that must sum to a given total.
For instance, look at the 20 at topleft of the puzzle on the cover. This 20 means that the four cells that meet at that point (squares 1,2,10,11 in the puzzle grid) must sum to 20. Since all the squares are within the same region of the grid (this is the same for every sum in the grid) then we know that there are no repeats allowed. Therefore they could be 1+4+6+9 to get to 20, for instance, but they could not be 6+6+7+1 since that would involve the repetition of a 6 which is against sudoku rules.
As you'll see, they add a delightful maths element familiar to killer sudoku, and are in fact great practice for that puzzle type as you'll get really familiar with the possible sums that can be made from groups of four squares.
It will come as no surprise that to solve group sum sudoku, and indeed any variant of sudoku that involves some maths, to look for combinations that have the least possible options  this generally means the lowest and higher options. For instance since 1+2+3+4 is 10, then if you ever see a 10 circle in the grid, then you can instantly write in the four options for each square. Likewise, 6+7+8+9 totals 30 so against if you see a 30 in the grid  as is the case with the cover image (middleleft) then you know the location of the 6,7,8,9 instantly.
All these puzzles can be solved using logic alone  there is never any guessing required. And full solutions are included at the back of the book, so if you get stuck solving any of the group sum sudoku puzzles then it is easy to consult the answers and find that digit that just might provide some inspiration and help you reach the rest of the solution unaided.
Printed on quality white paper in clear black ink, we hope you'll really enjoy this sudoku book  and, if you do, be sure to check out our many other variant sudoku puzzle books  we have an unparalleled range and variety of sudokustyle variant puzzles available for those who enjoy puzzles in this niche.Interested in buying this book or would like further information and to look inside? This book is available to buy from Amazon for £4.99. Click the button below to view the book on Amazon:
