If you're looking for a brain-stimulating, screen-free activity, the best Sudoku books have you covered. (In fact, research shows that brain teasers can reduce stress and keep your memory sharp.

Play Kiplinger Sudoku for free every day. Challenge yourself with the hard version, then see if your friends can beat your time. There's a new Hard Sudoku to try every day. When you purchase ...

(PhysOrg.com) -- A new analysis of number randomness in Sudoku matrices could lead to the development of more difficult and multi-dimensional Sudoku puzzles. In a recent study, mathematicians have ...

A public transport novice, I found it hard to focus on books or articles, for fear I’d miss my stop. But sudoku allowed my mind to easily toggle back and forth between the puzzle page and the ...

By Isaac Aronow Everybody can solve a hard Sudoku. Maybe not right now, maybe not without some practice, but trust me, it’s possible. By the end of this article, you’ll be equipped to tackle ...

Solve the grid in this hard Sudoku puzzle! The objective of Sudoku is to fill each row, column and sub-grid with exactly one of each number from 1-9. A conflict arises if you repeat any entry in ...

The heroines of Roxane Gay’s new short-story collection, “Difficult Women,” seem utterly ... A woman married to a twin (twins are a theme in this book) wears dark makeup because her husband ...

When you get stuck on a fiendishly difficult sudoku, it’s hard not to wonder if the puzzle really has a solution. At another moment, aglow in the triumph of a clever deduction, you might have a ...

A Finnish mathematician has concocted what he claims to be the toughest Sudoku the world has ever seen. Arto Inkala has come up with what he describes as the ‘Everest’ of numerical games in ...

But those who find our number puzzles a bit of a doddle may wish to sharpen their pencils for the ultimate test: what is claimed to be the world's hardest sudoku. The Everest of numerical games ...