Inequality Sudoku

Inequality Calcudoku

Inequality Calcudoku puzzle

Here’s a fun little puzzle – a Calcudoku Inequality puzzle.

Just place 1 to 6 into each row and column whilst obeying the bold-lined cages’ operator totals. These give the result of applying the stated operator between all numbers in that region, so for example the result of adding together all the squares in a ‘24+’ region must be 24. Similarly the squares in the 1728x region must all multiply to that total. Unlike in Killer Sudoku, you can repeat a value within a cage (but you must still obey the constraint to not repeat a number in a row or column).

There are also some inequalities marked. These show that the value of one square is lower than the value of a square next to it. The arrow always points to the smaller number.

Good luck! :)

Samurai Star Inequality

Samurai Star Inequality puzzle

I’m tempted to just say “good luck”, because frankly I think you’ll need it!  Not of course in the literal sense, since this is an entirely logical problem, which requires absolutely no guess work, but in terms of finding the right areas to make progress quickly.

So having started at the end, let me introduce you to this Samurai Star Inequality puzzle.  In all cases the “<” and “>” arrows point to the smaller number of each pair.  Other than that it’s a regular Samurai Star – place 1 to 9 into each row, column and marked 3×3 box of each of the 5 underlying 9×9 grids (including the one in the centre).

And now back to the beginning: Good luck! :-)

Inequality Sudoku

Inequality 2-grid Samurai Sudoku

Inequality jigsaw 6×6 Sudoku puzzle

On the Sudoku Xtra forums Marilyn suggested the great idea of an inequality Samurai puzzle for issue 2, so I’ve been having a look at doing this. And here’s the first result!

I’ve started off with a regular 6×6 jigsaw Sudoku, but have added inequalities, just to get you warmed up, then I’ve included my first ever Samurai Inequality Sudoku puzzle, albeit a 2-grid one for now.

You’ll notice in both puzzles here that I have included all inequality arrows, so you have far more information than you need – this is deliberate, to make them easier! On the 6×6 puzzle there are five really nice diamond shapes in the centre area, but in general I think having all the arrows is ugly (or lazy!) so I don’t plan to include them again in future (just as I’ve never included them in past published inequality/Futoshiki puzzles).

The rules of Inequality Sudoku are pretty simple – just place the numbers as you would in a regular Sudoku (or regular Jigsaw Sudoku in the 6×6 case), but obey the less-than (”<”) and greater-than (”>”) signs between squares.  These indicate that the value of the number in a square is either less than or greater than its neighbour. And that’s it! :)

Good luck!